Big flavor, light texture: Try this easy, moist keto lemon mug cake with a deliciously zingy lemon glaze. It contains only 6 ingredients and cooks in 90 seconds.
This flavorful keto mug cake is a new favourite of mine and I have made it several times already.
It is an almond flour sponge cake with a moist yet light and airy crumb texture and it is packed with zingy lemon flavor. I have topped it with a creamy lemon glaze.
Think of this cake as a super-speedy cheat's version of this Keto Lemon Pound Cake.
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🌟 Why You'll Love This Recipe
- This cake is ready from scratch in 3 minutes. It is brilliant as a spontaneous treat or as a last-minute dessert.
- It is naturally gluten-free and keto friendly with only 2.7g net carbs per portion.
- I shared the cake in the recipe video with a diabetic neighbour who popped by. She thought it was "divine". But, my carb-loving children also enjoyed the taste. This is a sugar free dessert that does not taste sugar free!
Ingredients
You only need 6 ingredients!
- Almond flour - I've made this cake with both super-fine almond flour and with ground almonds. When using almond meal or ground almonds, add 1-2 additional tablespoons.
- Heavy cream - also called double cream. We are using this instead of butter.
- Powdered sweetener - I used powdered erythritol. You can also use monk fruit sweetener or erythritol blends such as Swerve. Xylitol and allulose work as well.
- Egg - large
- Lemon juice - Fresh lemon juice tastes best. However, bottled lemon juice will also work.
- Baking powder
Instructions
This section contains step-by-step instructions and photos that show how to make this recipe. See the recipe card for full information on ingredients and quantities
Step 1: Mix the dry ingredients - almond flour, powdered sweetener and baking powder in a small bowl.
Step 2: Add the wet ingredients - lemon juice, cream and an egg. Mix with a fork until combined.
Step 3: If you want to turn the cake out onto a plate later, transfer the cake batter into a well-greased bowl or ramekin. Or, separate the mix into 2 mugs.
If you want to eat it straight from the bowl, microwave in the bowl you mixed the batter in.
Step 4: Microwave on high for 90 seconds.
Step 5: Turn the keto lemon mug cake out onto a plate and top with lemon drizzle glaze.
Or, enjoy it straight from the bowl!
Top Tip
I've had my fair share of microwave mug cake accidents! If your mug, ramekin or dessert bowl is too small, the batter will overflow as it rises and make a mighty mess.
It's important that your vessel has a volume of at least 200 millilitres and is wider rather than narrow and tall. Mugs or ramekins should not be filled with batter more than half. Always have a few fingers of free space between the batter and the rim.
Recipe FAQs
Use coconut cream or coconut oil instead of the cream.
No, you would have to change other parts of the recipe too. Make my coconut flour mug cake and add lemon.
It's not necessary for the recipe. However, I think it makes the cake taste even better.
Variations
Here are ideas how you can change up the recipe:
- Poke little holes into the finished cake. When you pour over the glaze it sinks into the holes and makes the cake even more moist.
- Add 1 teaspoon of poppy seeds.
- Grate lemon zest into the batter.
- Add a few blueberries or raspberries into the batter.
- Use lime instead of lemon
- Blend the egg with an electric mixer until double in size and pale in colour. This will make for an even lighter sponge.
- Add a cream cheese frosting (2 tablespoon cream cheese, 1 teaspoon sweetener and a little lemon juice)
- Top with sugar free whipped cream
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 sugar free lemon mug cake recipe:Â
- 600W = low power. 110+ seconds.
- 800W = 100 seconds.
- 900W = 90 seconds.
- 1000W = 80 seconds
- 1200W = 60-70 seconds.
After these times, check whether the cake is done. If it's still undercooked, add increments of 10 seconds.
Oven Instructions
To make this cake in the oven, bake for around 12-15 minutes at 180 Celsius (160C fan) or 350 F (320F fan assisted). Test with a toothpick of knife to make sure it's fully cooked.
Baking in 2 ramekins means less oven time, using one larger ramekin will increase the baking duration.
Storage
Refrigerator: Store leftovers in the fridge for up to 4 days.
Freezer: All almond flour cakes are suitable for freezing. Freeze for up to 3 months.
Related Recipes
I adore mug cakes. My first attempt at making a cake in the microwave was this divine low carb Christmas pudding.
Since we don't eat Christmas food all year round, I expanded my repertoire quickly. Try this keto chocolate mug cake, my vanilla keto mug cake or this divine keto peanut butter mug cake. Here are more keto mug cakes to try:
- Keto Blueberry Mug Cake4 Minutes
- Keto Lava Mug Cake4 Minutes
- Cinnamon Swirl Coconut Flour Mug Cake4 Minutes
- Keto Mug Cheesecake (Microwave Recipe)8 Minutes
Tried this recipe? Give it a star rating below!
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Recipe
Keto Lemon Mug Cake
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.
Ingredients
For the cake
- 4 tablespoon almond flour extra fine, or 5-6 tablespoons ground almonds
- 2 tablespoon heavy cream
- 1 ½ tablespoon powdered sweetener
- 1 egg
- 2 tablespoon lemon juice
- ½ teaspoon baking powder
For the glaze
- 1 tablespoon unsalted butter
- 1 tablespoon heavy cream
- squeeze of lemon juice
- 1 tablespoon powdered sweetener
Instructions
Cake
- Grease 2 ramekins, mugs or 1 microwave-safe bowl with melted butter. I used a glass dessert bowl.
- 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 more almond flour.
- Transfer batter into your bowl or mugs and level the top.
- Microwave on high for 90 seconds.
- Turn upside down onto a plate once cooled or enjoy straight from the bowl.
Glaze
- Melt the butter, then stir in the cream, lemon juice and sweetener.
- Let cool until the glaze begins to thicken. Spoon or pour over cake.
Video
Notes
- 600W = low power. 110+ seconds.Â
- 800W = 100 seconds.
- 900W = 90 seconds.Â
- 1000W = 80 seconds
- 1200W = 60-70 seconds.Â
Kathy
Oh 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
I love poppy seeds in lemon cakes as well. Happy the cake turned out well and that you like it!
Sarah
This 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
Hi 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
I 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
I 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
I 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
Hello 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
I used a duck egg which is very late and mine came out wet as well but tasted great.
Shari
This 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
Great news! I'm glad you liked it.
Julie
This looks very good. Can I use coconut oil, or butter instead of heavy cream?
Katrin
I think that would work, too. It's all about getting the wet/dry ratio right.
Michelle
Wow! Awesome fluffy cake recipe; and low carb, too. Super impressed!
Katrin
Hurray! Glad you enjoyed it:)
Sheila French
Delicious! 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.
Rosanne Gonzalez
Lemony, 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
Glad you liked it! And good to know it works to mix flours.Thanks for sharing!