Big flavour, light texture: Try this easy, moist and sugar free lemon mug cake with a deliciously zingy lemon glaze. Low carb, gluten free, keto and suitable for diabetics.
We moved house a couple of months ago, and our new kitchen came with a fitted microwave. We’ve been using it every day. Sod the rays. Microwaves are so practical! We’re living with our mobile phones permanently attached to our ears. We’re breathing in the fumes of London. I drink wine. In the scheme of things, how much more damage are a few microwave rays really going to cause?
Especially when a microwave can produce such a wonderful thing as a sugar free lemon mug cake!
This mug cake, my friends, is a revelation. To think that you can make a perfectly delicious, super easy lemon cake that’s ready in 3 minutes!
By the way, my first attempt at making a cake in the microwave was this divine Low Carb Christmas Pudding.
A sugar free lemon mug cake was a logical follow-up, because one cannot eat Christmas food in, say, July without it feeling a bit odd. Lemon cake, on the other hand, is an all-rounder. A bit like this keto chocolate chip mug cake, which is a must for chocolate lovers 😉
Let’s get right to it! This is how you make an easy lemon cake recipe in a mug:
1.) Mix your dry ingredients – almond flour, powdered sweetener and baking powder. Powdered sweetener works better than granulated sweetener in this recipe. You can make your own powdered sweetener by blending your granulated sweetener in a food processor or in the attachment of your stick blender.
2.) Add your wet ingredients – lemon juice, cream and an egg and mix with a fork.
3.) If you want to turn your lemon mug cake out onto a plate later, transfer the mixture into a bowl or ramekin which you have greased with melted butter. Or separate the mix into 2 mugs.
4.) This is how your cake looks after it’s been microwaved on high for 90 seconds! It’s moist and spongy – perfect 🙂
5.) Now you turn your lemon cake out onto a plate and top with your lemon drizzle glaze, which you have made with melted butter, cream, a squeeze of lemon juice and powdered sweetener.
6.) Serve and enjoy! Hard to believe this is a sugar free cake, right??? My kids, who are by default brutally honest, absolutely loved it. The cake I shot the recipe video of I shared with a diabetic neighbour who popped by. She also gave it a thumbs up 🙂 I think this is proof enough – lemon mug cake is officially a THING!
Baker’s notes
I think the portion size is quite generous. If you’re not ravenous, you could easily share this mug cake between 4 people, especially if you’re making it with the glaze. I have, however, calculated the nutrition for 2 servings.
You should definitely NOT skip the glaze, because it propels the cake from a delicious dessert into a decadently delicious dessert. If you wanted, you could even poke little holes into your lemon cake after you take it out of the microwave. That way, when you pour over the glaze it sinks into the holes and makes the cake even more moist and yum.
If you’re adventurous, you can even add some poppy seeds or grate some lemon zest into the batter.
I’ve made this cake with both fine almond flour and with ground almonds. If you use almond meal or ground almonds, which are coarser than fine almond flour, add 1-2 additional tablespoons of it so your batter isn’t too liquid.
Made this recipe? Give it a star rating below!
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Sugar Free Lemon Mug Cake (Low Carb Recipe)
Big flavour, light texture and ready in 3 minutes: Try this easy sugar free lemon mug cake with a deliciously zingy lemon glaze.
Ingredients
For the cake
- 4 tbsp almond flour extra fine
- 2 tbsp double/heavy cream
- 1 1/2 tbsp powdered sweetener
- 1 egg
- 2 tbsp lemon juice
- 1/2 tsp baking powder
For the glaze
- 1 tbsp unsalted butter
- 1 tbsp double/heavy cream
- squeeze of lemon juice
- 1 tbsp powdered sweetener
Instructions
- Grease the inside of a ramekin/2 mugs or microwave-safe bowl with melted butter. I used a glass dessert bowl.
- For the cake: Mix all dry ingredients - almond flour, sweetener and baking powder - in a separate bowl.
- Add all wet ingredients and mix thoroughly with a fork. If you find your dough is too liquid add a bit more almond flour.
- Transfer batter into your ramekin/small bowl and level the top.
- Microwave on high for ca 90 seconds. You can also bake the cake at 180 Celsius/360 Fahrenheit for ca 15 minutes.
- Remove from microwave and turn upside down onto a plate.
- For the glaze, melt the butter, then stir in the cream, lemon juice and sweetener.
- Let it cool until the glaze begins to thicken but can still be poured. Then spoon/pour over cake and serve.
Recipe Video
Recipe Notes
If you wish, you could add 1 tsp of poppy seeds.
For my UK readers: If you want to use ground almonds, you need to add 1-2 additional tablespoons as ground almonds are coarser than almond flour.
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Starting out on low carb? Find out all about my top 10 essential low carb kitchen gadgets!
Violeta says
May 17, 2019 at 6:32 pmPerfect!
Eleanor says
May 13, 2019 at 5:54 pmOh my gosh, YUM!!! I MADe with coconut milk in stead of heavy cream. It was so good. Thank you yet again for another delicious recipe.
Eleanor says
May 13, 2019 at 4:58 pmYUM!!! SO good. I made with coconut cream instead of heavy cream, turned out just as good. Thank you for yet another great recipe!!
Katrin says
May 13, 2019 at 5:49 pmGood to know you can use coconut cream!
Joy Robinson says
May 7, 2019 at 12:41 amFollowed the recipe to a “T” and it was very runny… Didn’t bake up at all. Checked and triple checked the measurements. Should it be more than 4 TB of almond flour? I am a lemonaholic and am beginning to experience withdrawals. ;). Help
Katrin says
May 7, 2019 at 7:30 amHi Joy, I have made the cake with both super fine almond flour and with ground almonds (=much coarser). If your almond flour is NOT super fine or you’re using ground almonds/ almond meal, you have to use an extra 1-2 tbsp of “flour”, it’s all in the recipe notes at the bottom. I’m sorry you seem to have missed it. Next time, just add more almonds util you have reached the same batter consistency as shown in the video – soft, but not runny.
Tammy says
March 29, 2019 at 12:12 amMy cake turned out bitter. I used So Noirished Monk Fruit Erythritol Blend in the measurement you gave. I used the same sweetner in the glaze and it tastes good. I’m not sure where I went wrong.
Katrin says
March 29, 2019 at 2:25 pmHi Tammy, the only ingredient that could taste bitter would be the lemon zest, if you grate in too much of the white peel. Or if you use waxed lemons, which means you might be able to taste the wax and chemicals. Or your almond flour was old and has gone off. You should always store it at room temperature if you’re not using it often. Do you think it could have been any of these?
Susan says
March 27, 2019 at 7:57 pmWOW!! Thank you so much for this delicious recipe, Katrin! It is truly the best mug cake that I’ve ever made – so good!! The texture was light and fluffy and the lemon flavour was just perfect.
I added the zest of one lemon, and replaced the cream with coconut milk. I also skipped the glaze, but I didn’t miss it at all. I plan to try making it with tigernut flour, in place of the almond, next time around.
Thanks again!!
Karyn says
March 4, 2019 at 9:25 amI love your easy to follow instructions and this lemon pudding was so quick and easy to make and best of all – it was delicious!
Katrin says
March 4, 2019 at 9:53 amThat’s so good to hear Karyn! Thank you for your kind words.
Gayle says
March 11, 2019 at 1:14 amTried the recipe 2 times and both times failed. Followed recipe to a T. 90 seconds wasn’t long enough so 2nd time it only was done around the edges. Please advise, we love lemon deserts.
Gayle
Katrin says
March 11, 2019 at 8:03 amHi Gayle, I’m so sorry to hear this! If you measured all ingredients, then I can only think your microwave must be less powerful and you may need to increase the time you cook it.
jeannie says
February 27, 2019 at 3:13 amHi Katrin, just made this before going to bed LOL it’s very yummy . Did you post macros anywhere?.
Katrin says
February 27, 2019 at 8:25 amYes, the nutrition info is in the recipe card 🙂
Linda says
February 24, 2019 at 8:30 pmJust made and ate, wonderful taste and texture. Used bottled lemon juice and confectioner sugar to sweeten. Great recipe to play with and no huge processed leftovers to gorge on.
Ranjit says
February 12, 2019 at 12:02 pmHi!I’ve tried your recipe and it’s great!do you think I could add cream cheese here or sub the hc?will it ruin the cake?thanks a lot!love your recipes
Katrin says
February 12, 2019 at 2:03 pmYes, I think cream cheese could work in place of the heavy cream – I haven’t tried it, but they have a similar consistency.
Louise Allison says
January 27, 2019 at 12:04 pmNot usually a mug cake fan – they leave me a bit ‘meh’ – but fancied something lemony! Just made this, & as I fancied a big lemon hit, I doubled the lemon in the cake & sauce (will add zest next time, but my lemons were a bit aged!!) ….. so then I needed to add more almond flour to get it less runny…… cooked for about 3.5 mins in micro (coz it was maahhooosive!!) Turned it out into a bowl, stabbed it, & drizzled the sauce over…… lush!! It will make 12 servings for me, as it’s super filling….. but just served it with sour cream and a handful of blueberries & can honestly say it’s one of the tastiest sweet things I’ve eaten on keto…. So thank you very much!
Katrin says
January 27, 2019 at 7:19 pmThanks for sharing your microwave timings for doubling the recipe!! And I love it that you loved it!!
Naomi says
January 11, 2019 at 5:30 pmThis is delicious, Thank you! Mine was wet also, I nearly used less liquid but made it per recipe, except I added shredded lemon zest and used 1 TBSP of swerve. very tangy, delicious, just about perfect, even very moist.
Katrin says
January 11, 2019 at 6:14 pmGreat news! Glad it worked out 🙂
Kris says
January 10, 2019 at 8:12 pmI made this cake today. The lemon flavor is great! But mine was quite wet when it was still a batter. Since I had followed the directions completely I went ahead and cook it and it was of course quite soft. The cake itself turned out quite flat not nearly as beautiful as your picture. Like I said the flavor was good.
Katrin says
January 11, 2019 at 10:00 amIf your batter did not have the same consistency as mine (shown in the video), you should add more almond flour next time.
Annette says
January 9, 2019 at 7:29 amAwesome recipe!! The best Keto friendly mug cake I’ve made (and I’ve tried a few). I’ll try the lemon zest and poppy seeds next time! When I made mine, I sprinkled a little unsweetened medium coconut over top. It created a wonderful texture and just added a little extra to the look!
Thanks for creating this recipe!!
Annette
Victoria BC, Canada
Katrin says
January 9, 2019 at 12:46 pmThat’s good to hear – I’m glad you like it. 🙂
Audrey RIETHMULLER says
October 25, 2018 at 10:57 amJe viens de teste et j’adore. Merci pour cette recette
Katrin says
October 25, 2018 at 11:13 amYou’re welcome Audrey!!!! 🙂 Thank you for your comment
Lorie Marshall says
January 7, 2019 at 1:20 amI have made this last month December 2018, and it’s divine!! So easily in large mug,then slice in 1/2 once its sits for like 30 seconds cool down. Love it!!
Theresa C says
October 23, 2018 at 2:56 amMade this and did very little tweaking – it came out wonderfully! I did 70 seconds in a 1000 watt microwave to make sure it did not overcook. LEMON YUM! An bit of extract and 1 teaspoon of chia seeds 🙂
Katrin says
October 23, 2018 at 10:55 amGreat news! Thank you for your comment
Bree says
October 5, 2018 at 8:33 pmHi I have made this cake 4 times now and each time it either falls apart when I turn cup upside down or the top sticks to th3 bottom of the cup…what am I doing wrong. The cake tastes delicious but is really a mess
Katrin says
October 8, 2018 at 8:55 amI use a lot of melted butter to grease the bowl I use. It may be that you need to use some more butter. Or maybe it has to do with the shape of the cup/ramekin you use. My bowl is fairly flat. It may be harder to release the cake if you used a regular cup, for example (less diameter. The third thing that comes to mind is that you may try to release the cake while it’s still warm? It firms up as it cools down and would be less crumbly. Also, a container with a very smooth surface, such as glass. I hope this helps 🙂
Samantha says
September 12, 2018 at 2:18 pmI figured this would be like all the mug cakes I’ve made before, decent but nothing to rave about. I was so WRONG! This was sooo delicious.
Katrin says
September 12, 2018 at 2:37 pmThat’s so good to hear!!! Thank you 🙂
Heidi says
August 14, 2018 at 7:42 pmI made a banana variation of this, substituting banana extract and almond extract for the lemon juice. Amazing!!!
Katrin says
August 15, 2018 at 4:13 amOMG that sounds incredible!!!! Yumyumyum
Carol says
July 13, 2018 at 3:30 pmWhat can you use to be dairy free
Katrin says
July 13, 2018 at 4:03 pmHey, you can replace the cream with coconut cream (if you use coconut milk from a can, only use the firm part) and the butter with coconut oil
Alyssa says
July 7, 2018 at 9:08 pmJust made this. Absolutely lovely!! I’m such a citrus freak and have been missing a good lemon cake. This hit the spot.
Just one question. Is this reciipe a single serving? I split it into 2 mugs and it baked halfway up. Sorry not a great baker or cook
Katrin says
July 8, 2018 at 11:35 amHi Alyssa, it’s 2 servings – I always find almond flour to be quite filling. You could try using ramekins next time, if you have a couple (I did this for my chocolate chip mug cake), or tea cups. Glad the cake hit the spot!!!
Amanda says
June 3, 2018 at 6:44 amI only Have granulated sweetener. Would that not work for this recipe?
Katrin says
June 3, 2018 at 7:56 amYou should be fine using granulated sweetener too. Because it’s heavier, you might need a little less of it. Just try your batter and see what you think!
Tammy says
August 19, 2018 at 12:40 pmIf you run your granulated sweetener in a food processor for a few minutes in pulse position it turns into a powder.
Pru says
May 24, 2018 at 1:59 pmAbsolutely delicious, I’m on a keto diet and was craving for a cake, I made it and it was gone in seconds. Thank you.
Katrin says
May 24, 2018 at 2:54 pmThat’s great to hear! Thank you for your comment 🙂
Linda Reichert says
May 2, 2018 at 3:48 amthis was great..and I mean great!..made it tonight. Company worthy to make! added the poppy seeds..elegant look..so fast to make…..
Katrin says
May 2, 2018 at 9:14 amGlad you liked it Linda!!
Laura says
April 28, 2018 at 3:01 amWhat an exceptional treat! I’ll be making this again…maybe in an hour!
Katrin says
April 28, 2018 at 1:16 pmHa, this sounds like you’ve found a winner 🙂
Trish says
April 2, 2018 at 4:07 amThis looks yum!
Great idea 🙂
Kathy says
March 24, 2018 at 12:52 amOh my goodness this was delicious. My husband and I shared it but I think next time we will each have one. I might use some lemon zest to add a zing. Couldn’t post a picture because it didn’t last long enough lol. Enjoyed it with a cup of Lady Grey tea. Thank you!
Katrin says
March 26, 2018 at 8:16 amYou’re welcome! We also found it hard to share, haha 🙂 I agree adding lemon zest would be great here. I might add that as a suggestion in the recipe. Thank you for your comment!
Jane says
March 13, 2018 at 7:17 amAdded poppy seeds and followed the recipe step by step. This cake is really moist and so easy to make. A keeper!
Katrin says
March 13, 2018 at 10:20 amI love poppy seeds in lemon cakes as well. Happy the cake turned out well and that you like it!
Garbo says
March 13, 2018 at 1:16 amIt turned out perfect! Delicious
Katrin says
March 13, 2018 at 10:18 amBrilliant! Thank you for your comment. I’m glad you like it 🙂
Sarah says
March 4, 2018 at 6:16 pmThis looks delicious! And I use powered swerve instead of erythritol? Swerve is the only powdered sweetener I have right now my erythritol is granulated. Can I use regular butter for the glaze? Or will it mess it up? I only have regular butter right now. I can’t wait to try this!
Katrin says
March 5, 2018 at 11:40 amHi Sarah, any powdered sweetener would work fine. As for the butter, do you mean salted butter? If so, then I’m not sure – I can imagine salted butter with chocolate, but not with lemon 🙂 Maybe use more cream instead?
Kate Watson says
February 21, 2018 at 10:14 amI tried this out got the first time tonight. It also turned out wet and crumbly but on reading the author’s comments about the almond flour, I realized mine was quite coarse – not fine and dry. It was delicious all the same. I didn’t even wait for the glaze to cool down… but I will try this again until I get it perfect!
Katrin says
February 21, 2018 at 7:24 pmI love eating my cakes straight out of the oven… Glad you liked it, even if it was crumbly. Almond flour can differ so much in texture. Fingers crossed next time you’ll nail it!
Holli says
February 19, 2018 at 8:53 pmI also had the problem of it coming out too wet. I tried putting it in the microwave a bit longer and it didn’t really seem to help. I wondered if it had anything to do with size of egg maybe? I used a large egg. Do you think that would make a significant difference? The flavor is still really nice. I loved how simple and quick it was to make as well.
Katrin says
February 20, 2018 at 9:59 amHello Holli, I think it cannot really have anything to do with the egg, because if you’d microwave it for long enough it would set eventually. If the recipe contained too much egg if would taste eggy, that’s the only disadvantage I can think of. I think it may have something to do with the almond flour you used. Brands can vary quite a bit in texture. The one I used is super fine. If you used almond flour that is ground coarsely it would absorb less moisture and your cake might end up soggy. Next time you use the almond flour you have in this recipe, try reducing the amount of liquid (a bit less cream, a bit less lemon juice).That should do the trick. Or try out the almond flour I used (Sukrin) – you can get it on Amazon. I hope this helps.
Louise says
June 14, 2018 at 2:39 amI used a duck egg which is very late and mine came out wet as well but tasted great.
Shari says
February 19, 2018 at 3:31 amThis was delicious! My favorite mug cake so far. I made it in two ramekins and the only problem I had was that it came out quite wet and fell apart a little BUT it may have been my fault because I didn’t have heavy cream and had to use 1/2 & 1/2. It was still absolutely delicious and held its shape well enough, was just very soft. For the glaze, because I didn’t have powdered sweetener I used stevia drops and to keep it from being even thinner (due to using liquid), I subbed lemon essential oil drops for the lemon juice. It was a thin glaze, but very delicious. Can’t wait to make this again. I topped it with a little bit of whipped cream and shared it with my non-low carbing husband and he said it was very good and he’d love to have it again. Thank you so much for sharing the recipe!
Katrin says
February 19, 2018 at 10:10 amGreat news! I’m glad you liked it.
Julie says
February 9, 2018 at 1:03 pmThis looks very good. Can I use coconut oil, or butter instead of heavy cream?
Katrin says
February 9, 2018 at 4:30 pmI think that would work, too. It’s all about getting the wet/dry ratio right.
Michelle says
February 8, 2018 at 12:49 amWow! Awesome fluffy cake recipe; and low carb, too. Super impressed!
Katrin says
February 8, 2018 at 11:02 amHurray! Glad you enjoyed it:)
Sheila French says
January 25, 2018 at 3:14 amDelicious! It turned out perfectly. I am happy to have this sweet treat.
One question: is the fat content correct in the nutrition section? It looks off to me.
Katrin says
January 25, 2018 at 11:00 amGlad you like it! I’ll double-check when I have a minute regarding the fat content. I use a free website called sparkrecipes to calculate the nutrition. Do bear in mind though that almond flour is relatively high in fat – unless you use a reduced fat version like the Sukrin almond flour. If you add the butter and double cream…
Rosanne Gonzalez says
January 18, 2018 at 4:47 amLemony, buttery, light and moist!! Delicious! Thank you for the recipe! I did use 1 tbsp coconut flour in place of one of almond flour. I find that it gives it a better flavor.
Katrin says
January 18, 2018 at 1:51 pmGlad you liked it! And good to know it works to mix flours.Thanks for sharing!
Caryn says
January 14, 2018 at 4:59 amJust tried this..was a bit grainy is that typical of almond flour? I did use super define.
Katrin says
January 14, 2018 at 6:57 pmAlmond flour is a bit more grainy than regular (wheat) flour. That said, brands differ a lot. Some are ground coarser than others. From my experience, the finest flours are the ones that are cold pressed, i.e. where the fat has been extracted. It is lighter in colour and very fine.
Allison Wenger says
January 13, 2018 at 4:23 pm1/13/18 QUESTION… I LOVE this Lemon Mug Cake recipe. I’ve made it three times already. It’s turning out very acidic for me. I don’t want to lose the lovely texture of this cake, so how can I lighten up on the lemon juice but keep the cake the same? Maybe minus 1 Tbsp lemon juice, and add 1 Tbsp half-and-half/cream? For sugar I am using Swerve brand confectioners sugar (sugar-free sugar).
Katrin says
January 14, 2018 at 6:55 pmOf course, you can try that. A long as the dry/wet ratio remains the same, it would turn out the same texture. Everybody has different preferences, so it’s always great to experiment with recipes a bit until you figure out exactly how they work best for you. I’m glad you like the cake!!
Deborah L. McDonough says
December 27, 2017 at 9:45 pmOh, my. I just tried this and followed the recipe to a “t.” It was very mushy and fell apart when I tried to remove it from the bowl, so I scooped everything back in and microwaved it another 30 seconds for a total of two minutes. I have a large, powerful microwave, so it’s not that. Any ideas as to what I can do to fix this?
Katrin says
December 28, 2017 at 7:07 pmHi Deborah, I’m sorry to hear this. It must have something to do with either the quantities (did you use measuring spoons to measure the almond flour/cream) or the type of almond flour? The almond flour I used for this recipe is very fine, so if you were to use regular ground almonds like the ones you can buy in the supermarket baking section, for example, you would end up with a grainier texture that might tend to fall apart. I hope this helps?
Theresa says
December 23, 2017 at 4:03 pmCan’t wait to try this and several other recipes of SFL!
Katrin says
December 26, 2017 at 9:38 amAwesome! Write me a comment when you’ve tried it. I’d love to hear how you liked it!
Anny says
December 18, 2017 at 6:50 pmHello from Paris, France!
I had a craving for it as soon as I saw it! But no almond flour so I used chesnut flour… amazing! So subtle… thanks for the recipe!
Katrin says
December 18, 2017 at 9:00 pmMmmmmh, chestnut flour! Makes it kind of Christmassy, too… nice.
Kads Life says
December 18, 2017 at 6:51 amLooks delish! Is there an alternative flour I could use?
Katrin says
December 18, 2017 at 9:56 amHi there! You could try replacing the almond flour with 2 tbsp of coconut flour
joe says
February 5, 2018 at 10:04 pmI was wondering the same thing. I don’t see why not.
joe says
February 5, 2018 at 10:09 pmI just read another comment that coconut flour was used and it turned out great.
Doreen Jaeger says
December 17, 2017 at 5:56 pmAnother great recipe, Katrin. Thank you so much. I never thought I’d get into mug cakes, but you have certainly changed my mind!!!
Katrin says
December 17, 2017 at 6:11 pmThey have kinda changed my life, haha!
Janine says
December 17, 2017 at 5:54 pmI made this cake this afternoon when my mum came over and we loved it! She’s a type 2 and still loves her sweets.It was great to be able to serve her something that’s good for her AND tastes great.
Katrin says
December 17, 2017 at 6:10 pmHow wonderful! What I love about these mug cakes is that you can make them with minimal effort and at short notice (provided you have the right ingredients). If you see her again during the Christmas season, you could try my Low Carb Christmas Pudding, which is also a mug cake!
Heather says
December 16, 2017 at 4:05 pmCan you make this in the oven, too? I don’t have a microwave
Katrin says
December 17, 2017 at 6:13 pmYes you can! I haven’t tried it but would go with 180 Celsius (nut flours bake at lower temperatures than wheat flour) for ca 15 minutes, maybe a little longer. Check if it looks nicely browned and if it’s done inside!
shirley says
April 22, 2018 at 4:49 amI doubled the recipe, and only one t. Of Stevia for cake and glacé. Had to cook extra 15 min. Even though separated into two ramekins. Turned out great with these adjustments.
Katrin says
April 22, 2018 at 10:06 amGreat! Thanks for sharing 🙂
Vendela B says
December 16, 2017 at 4:04 pmI love mug cakes! This one looks good. Will definitely try.
Katrin says
December 17, 2017 at 6:14 pmThank you!! Let me know how you get on!
Audra Lee says
January 15, 2018 at 12:14 amI made this tonight. It turned out great! Thanks
Katrin says
January 15, 2018 at 1:05 pmBrilliant! Thanks for commenting 🙂