Big flavor, 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!
Why you'll love this sugar-free mug cake
This mug cake, my friends, is a revelation. It is such a treat. To think that you can make a perfectly delicious, super easy lemon cake that's ready in 3 minutes! It's like the super-speedy cheat's version of this Keto Lemon Pound Cake.
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.
I have a bunch of keto mug cake recipes on my website. Try this keto triple chocolate mug cake, which is a must for chocolate lovers, my Keto Vanilla Mug Cake or this divine Keto Peanut Butter Mug Cake.
How to make a keto lemon mug cake
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.
Microwave timings
My microwave operates at 900 watts and my cake took 90 seconds to cook. Here's a quick overview of recommended baking times for this low carb lemon mug cake recipe:
- 600W = low power. 110+ seconds.
- 800W = 100 seconds.
- 900W = 90 seconds.
- 1000W = 80 seconds
- 1200W = 60-70 seconds.
Oven instructions
To make this sugar-free mug cake in the oven, bake for circa 15 minutes at 180 Celsius (160C fan) or 350 F (320F fan assisted).
Made this recipe? Give it a star rating below!
Love lemon? Try these zingy recipes:
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Sugar Free Lemon Mug Cake (Low Carb Recipe)
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary. ***As an Amazon Associate I earn from qualifying purchases.
Ingredients
For the cake
- 4 tbsp almond flour extra fine
- 2 tbsp double/heavy cream
- 1 ½ tbsp powdered sweetener
- 1 egg
- 2 tbsp lemon juice
- ½ 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 circa 90 seconds. You can also bake the cake at 180 Celsius/360 Fahrenheit for circa 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.
Video
Notes
Nutrition
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Lorna says
I recently had to reduce my intake of sugar and found your recipes amazing and help with my need for some sweet treats. Your sugar free lemon dessert cake was delicious, especially with the syrup!! Do you have any sugar free coffee desserts?? Thought next time I would try and adapt the lemon cake that is so light and enjoyable. Thank you!
Katrin Nürnberger says
I think you can quite easily replace the lemon juice with coffee. Maybe also add 1 tsp of cocoa powder. Should work well!
Irma says
Love this cake! I gave the second one to my sister, who is pre-diabetic, to show her that dessert can be low carb. She loved it, too!
Katrin Nürnberger says
So glad you both enjoy the recipe!
Shaista Abdullah says
Delicious and moist and lemony.... thank you for sharing this
AL says
Hi I just made your chicken soup which was amazing so thought I'd look at other recipies. This cake looks great but I can't tolerate any alternative sweeteners ( I've tried them all - even ones I exported from the US at great expense!) My stomach struggles with them all. What would you recommend re maple sryup or something like that? How much could I substitute? I know the point of your site is "sugar free" but I'd really appreciate any suggestions.
Katrin Nürnberger says
I think you could try using either maple syrup or coconut sugar. And try to use as little as possible... plus eating sweets only as part of a meal and not separately to reduce blood sugar spikes.
Linda Swoveland says
I have everything I need to make this lemon mug cake except, almond flour and double heavy cream. I've actually never heard of
(double) heavy cream. I hope that I'm able to find it.
I don't need to lose weight but I'm on a low carb diet for type 2 diabetes. I'm craving something sweet. This cake will certainly satisfy my sweet tooth.
Thank you
Katrin Nürnberger says
Hi Linda, here in the UK we say double cream, and in the US it's called heavy cream. I used both terms so everyone understands what I mean - sorry if I confused you! Double cream has around 45% fat.
Ruth Baucom says
Wow this might be the fluffiest cake I’ve made since being on keto. Can’t believe I made it in the microwave.
Katrin Nürnberger says
So glad you like it!!
Iwona says
Hi Katrin,
Is there possibility to bake it in the oven instead mikrowave?
If yes, how long and what temperature should i bake it in?
Thanks,
Iwona
Katrin Nürnberger says
I would do 180 C / 350 F and about 12 minutes. Then check if it's done!
Paulette says
Hi before I try this can you please let me know how much in grams or millilitres is the term “ tablespoon”please? I don’t actually have a tablespoon in my flat - only dessert spoons but I do have a scales and a measuring jug!
Looking forward to trying it out but rather nervous as I am no cook!
Katrin Nürnberger says
1 tbsp almond flour = 6 grams. 1 tbsp liquid = 14 grams. 1 tbsp sweetener = 12 grams. Hope this helps: )
Paulette says
Thanks,, it worked like a dream and is delicious. Can’t make enough!
Carol Machen says
One of my Husband’s favourite desserts. I add poppy seeds or lemon zest and make double the amount of sauce to go with it, very Yummy
Naomi says
Can you use coconut flour instead of almond flour? If so, how much coconut flour do you use for the recipe?
Katrin Nürnberger says
The rule of thumb is to use 1/3 of the amount stated for almond flour. In this case, it would be a maximum of 1 1/2 tbsp.
Stacey Dresser says
I made this last night and it was fantastic. Thank you for the recipe!
Daisy says
Is this calories per serving?
I love this recipe, thank you!!!!!
Katrin Nürnberger says
Yes, I always calculate per serving
Ewa says
Katrin, what's the power of the microwave you're using? I have a 1000W one, don't want to overdo it so will adjust the timing accordingly..
Katrin Nürnberger says
Glad you asked. My microwave is 900 W, so a bit shorter should work for you.
Gillian Anderson says
Would it be possible to substitute Greek yoghurt for the cream?
Katrin Nürnberger says
Yes, I think that could work!
Regine Theodore says
This cake is AWESOME!!! I substituted a vegan coconut cream aqua faba alternative heavy cream instead of dairy heavy cream. The cake is mindblowingly good. And thank you Katrin for including the macros. This cake might be big enough to share but it's so good that I am not sharing it!!
Lisa A says
This mug came sounds delicious. Will this recipe also work with lemon extract?
Katrin Nürnberger says
Of course it will - but you may want to use a little less almond flour to offset the missing liquid. It's all about getting the right wet/dry ratio. However, fresh lemon and a bit of lemon zest will ALWAYS beat any extracts in terms of taste and flavour.
Dorothy says
Are the nutritional values with icing included or before icing
Katrin Nürnberger says
Hi Dorothy, it's without the icing.
Maria says
Making this tomorrow for a friend who is diabetic. I did a test run tonight, and it is good and so easy. I'm going to double it tomorrow, making it in 2 ramekins so I can make a mini double layer cake. I love the idea of adding lemon zest. I'll try that, too.
Katrin Nürnberger says
What a great idea to turn it into a mini cake. Layer with frosting - that would be lovely!
Helena says
I regularly make a chocolate mug cakein a ramekin which I cut in half and then fill with mascarpone as a layered mini cake. Sometimes I add flavours to mascarpone, e.g. instant coffee and a bit of sweetener, or orange oil and orange zest. I think I will do something similar with this cake, but I will mix mascarpone with a bit of lemon juice, a few drops of stevia liquid, with some grated lemon zest to taste. If not lemony enough can also add a few drops of lemon oil. Then your glaze drizzled on top. Can't wait!
Katrin Nürnberger says
That sounds amazing. What a treat!
Lori says
I’m a chocoholic through and through but this was an amazing change of pace - light, refreshing, and tangy! I put a little lemon zest in the batter and added almost 2 extra tablespoons of almond flour; thanks for those tips. Yummy cake!
Katrin Nürnberger says
Always good to take a break from the chocolate once in a while 😉
Adeela says
Came out amazing. I added a little more Almond flour as instructed. Enjoy it in my sunday breakfast
Katrin Nürnberger says
Perfect breakfast!! 🙂
Lou says
Hi, I made this recipe for the first time last night, it was delicious! The glaze was absolutely lovely.
I added a bit of lemon zest to the sponge mix too, just for a little extra flavour.
I’ll definitely make this again.
Thanks!
Katrin Nürnberger says
I bet the lemon zest in the sponge mix was delicious 🙂
Laura says
This is my second “treat” recipe I have tried since last week when I made the pancakes. (Which were amazing, I’ve made them a few times already)
I followed directions exactly then added a couple more tbsp of ground almond. I also actually only have granulated sweetener, and soya cream rather than the proper stuff. So maybe exactly was the wrong word, ........ anyway, another super desert, really light, tastes great, The glaze is a must. had to eat the whole lot as my son decided it wasn’t for him, he’s only 7, he’s not on board yet.
I’d like to say thanks again for a great healthy Keto dessert.
Thanks very much.
Katrin Nürnberger says
Haha, this cake is way too ambitious for a 7 year old!!! But I'm happy you liked it 🙂
Keri says
This is a fantastic recipe! I also like the Chocolate Mug cake. Trying more of your recipes. They are terrific.
LJ says
I shaved the recipe in half (1 serving vs 2) and used half a serving of egg whites because I couldn't fathom using only 1/2 of an egg. Maybe that is why the cake was still a bit runny. I noticed this when I stopped the microwave at after 1min to check. So, I added 1tbsp of coconut flour. This made it spongy. The glaze was thicker than the demo, but I liked it. This will be my go-to alternative when I get bored with my usual keto chocolate mug cake.
Katrin Nürnberger says
Glad you liked it!!! And thanks for detailing your tweaks 🙂
cindy says
oooh...very delicious, are specs for 1 serving or two?
Katrin Nürnberger says
I always calculate per 1 serving 🙂
Ginny says
Delicious!! Perfect balance of sweet and sour, nice and lemony. Used lemon zest in batter as well as icing-so good! Thanks to Katrin's suggestion to observe how liquidy the batter is, I added a Tablespoon more of almond flour, turned out firm enough and still moist. Family all loved it, so need to go out to get more lemons. Thanks for this recipe, Katrin! (Can you figure out a way to add some frozen blueberries to this? Would be over-the-top!)
Katrin Nürnberger says
Hi Ginny, I'd say, just throw a few frozen (or fresh) berries in next time you make it. I'm sure it would be delicious!
Nancy says
I made this today using limes instead of lemons. It was great! I added some lme zest to the glaze and a little less sweetner in the glaze
Katrin Nürnberger says
Ooooh I'm sure it was amazing with lime! The taste of summer.... we need a bit of that!
Toni says
This was so amazingly good! And easy, had everything in the cabinet. Very satisfying and wonderful lemon flavor.
Katrin Nürnberger says
So glad you liked it!!! 🙂
Lynette says
OMG....just tried this tonight....absolutely yummy, will definitely make it again and sooner rather than later. The batter was slightly too wet for me so I added 2 extra tablespoons of almond flour...worked a treat........ I also added another tablespoon of cream in the sauce...Just because Hubby loved it to....I miss my sweet treats but this recipe is just perfect....thank you
Katrin Nürnberger says
Wonderful! Glad you made the recipe work. Almond flour can vary so much in texture, so my guess is yours must have been quite coarse.
Alix says
Lovely light sponge,really did enjoy this.
Katrin Nürnberger says
glad you liked it!!
Antonella Stalker says
Absolutely delicious! Followed the recipe and made two little cakes. Had one tonight and am having the second for breakfast! Cannot wait already. Thank you so much for the amazing recipes x
Katrin Nürnberger says
I love having cake for breakfast!!
Barbara says
ebook
Recipes well written and easy to follow. Can't wait to try them.
Katrin Nürnberger says
If you make something, do let me know how it went and give the recipe a star rating !