Need a personal-sized low carb cake for someone special that takes minutes to make? Try this gluten-free keto birthday cake in a mug! It only takes 2 minutes to bake.

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Low Carb Birthday Cake In A Mug
Even though you might be on a low carb diet, you can still celebrate your birthday with a sweet frosted cake! In fact, this cute little low-carb and gluten-free birthday mug cake only takes two minutes to bake in the microwave.
I admit that this cake baking thing in the microwave didn't really appeal to me at first, but after seeing a lovely Valentine's Day mug cake recipe from Sugar Free Mom, I was sold on the idea.
So, I want to thank my fellow low-carb blogger Brenda for turning me around.
Let me tell you- This cake is the perfect mini size. You won't spend a lot of time baking it, and you won't have any leftovers that you'll need to store afterward.
It is perfectly-portioned for just one person - so you get your own little personal cake! It makes 4 cute-sized slices.
Ingredients Needed For Keto Mug Cake
All of the exact ingredient amounts are in the printable recipe card at the bottom of this post. First, I'm going to share some more information about the ingredients.
Flour
To make this cake, I used a combination of almond flour and coconut flour because, out of all the flour combinations I tried, this gave me the perfect texture!
Liquid
Then, I added coconut oil and almond milk (because coconut flour soaks up wet ingredients).
Dry Ingredients
You'll also need baking powder, one egg, salt, and vanilla extract for the flavor and texture.
Sweetener
For the low-carb sugar substitute, I suggest either liquid or granular sweetener. Confectioner's substitute or brown sugar substitute will change the texture too much.
Frosting
I decorated this birthday cake with homemade keto buttercream frosting- This recipe is amazing!
It's whipping cream, sweetener, butter, cream cheese, and a few more ingredients. It's basically Heaven!
Please note: Check out the recipe card at the bottom for a full list of ingredients used to make this low carb recipe.
Quick Tips:
- There are 4.1g net carbs in half of this cake. If you are really trying to watch your macros, you can make just one layer and cut the amounts in half.
- If you like chocolate, you can make a keto chocolate frosting too. Sprinkle the birthday cake with sugar-free sprinkles or add some sugar-free chocolate chips on top.
- Mug cakes are typically baked in a cup and left in there. Since I wanted this to be a miniature double-layer frosted birthday cake, I used a 2-cup round Pyrex storage container for each cake layer.
- A regular ramekin is another great dish for baking these keto birthday cake layers. If you have a wide mug, that would probably work as well. You just want to make sure whatever you use is microwaveable.
How To Make A Keto Birthday Cake In 2 Minutes
This is such a simple recipe! All of the detailed steps and ingredients are in the printable recipe card just a little further down on this page.
Mix The Cake Batter
The first thing you will do is mix the dry ingredients in a separate small bowl. Set this aside.
Then, in the ramekin or small bowl that you'll make the cake in, melt the coconut oil. Stir in the almond milk, egg, sweetener, and vanilla extract.
Next, beat the dry ingredients into the liquid ones with a fork until they are really well combined.
Bake The Keto Mug Cake
Put it in the microwave and cook it for about 1 ½ minutes or 2 minutes Basically, take it out when it is completely set, like in the pictures below.
Take the little cake out of the bowl or mug and let it cool on a cooling rack for about 5 minutes.
This step is really important if you want to decorate it with frosting. If you skip this step, the frosting will melt and look more like a glaze.

Add Frosting and Decorate!
Finally, decorate your cake with some low-carb buttercream frosting. My cake looks so simple because I only made enough icing to frost the cake and didn't have any left to decorate with.
Had I planned things better, I would have made a double batch of frosting so I could do the traditional birthday cake frills. Oh well. Maybe next year!

What To Serve With Low-Carb Birthday Cake
There are lots of things you can serve with a keto birthday cake that won't kick you out of ketosis.
- Add a scoop of chocolate avocado ice cream on the side.
- Some other fun low-carb sweets that would taste perfect with this little cake are some keto shortbread cookies or chocolate chip dip.
- Don't forget the Bulletproof tea or coffee!
Frequently Asked Questions About Keto Mug Cake
Take a look at these often asked questions before submitting a comment. You may find the answer you're looking for here.
Can you use a plastic bowl or cup for a mug cake?
I'm not a fan of plastics or using them in the microwave so I don't recommend baking these cake layers in plastic dishes.
My Pyrex container was pretty hot taking it out of the microwave so use caution in removing the hot cakes. I also used potholders!

Can you make this mini cake in the oven?
This is a yellow gluten-free cake that bakes up nicely in the microwave, but you can bake it in the oven too.
Just follow my steps and then bake them at 350 degrees for about 15 minutes! Check on them after 10 minutes so they don't burn.
What is the best low-carb frosting to use on the cake?
The frosting I used was the recipe from my gluten-free coconut cupcakes. The amounts given in that recipe were just enough to frost this two-layer mug cake.
If you prefer chocolate frosting, there's a great recipe listed on my chocolate frosted zucchini brownies. This is the perfect cake to bake up when you are craving something sweet but don't want a lot of servings.

The Best Keto-Friendly Birthday Cake- In A Mug!
This mini birthday cake can be a fun activity to do with the kids. The size kind of reminds me of the cakes from the Easy Bake Oven that I used to make with my older daughter. Of course, this is a much healthier cake than the mixes we used back then.
When I want a larger cake to share with family and friends also watching their carbs, I bake up a gluten-free carrot cake.
Just make sure to use low carb flours and keto sweeteners to keep the carbs low!

Other Cake Recipes To Try
If you enjoyed this keto birthday cake, then here are some more keto cake recipes you should try next. They are some of my favorites!
- Keto Chocolate Molten Lava Cake has rich chocolate oozing from the middle, so it's pure decadence.
- Low Carb Pumpkin Spice Cake has 3 layers made from mug cakes, but with the pumpkin spice flavor that you love.
- Keto Lemon Mug Cake is bright and refreshing and another one of my favorite mug cake recipes.
- Paleo Strawberry Mug Cake is made with 2 cute little layers and a yummy buttercream frosting.
- Blueberry Mug Cake is a really simple low-carb breakfast idea that tastes like a blueberry muffin.
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Recipe

Keto Birthday Cake in Minutes
Video
Ingredients
Each Cake Layer:
- 2 tablespoons almond flour
- 1 tablespoon coconut flour
- ¼ teaspoon baking powder
- dash salt
- 1 tablespoon coconut oil melted
- 2 tablespoons plus 1 teaspoon almond milk
- 1 egg
- 1 tablespoon low carb sugar substitute
- ½ teaspoon vanilla extract
Optional:
- Low Carb Frosting I used Buttercream Frosting
Instructions
- Mix together almond flour, coconut flour, baking powder, and salt in small bowl. Set aside.
- Melt coconut oil in small round microwavable cup that will be used to bake cake. You can use a ramkin or 2-cup Pyrex storage container.
- With fork, stir almond milk, egg, sweetener and vanilla extract into melted coconut oil.
- Beat dry ingredients into liquid ingredients with fork until well combined.
- Microwave from 1 ½ to 2 minutes or until cake is no longer wet. It took 2 minutes to bake in my 900 watt microwave.
- Remove cake layer from pan and cool on rack.
- Repeat steps for each cake layer.
- Frost with icing if desired.
Notes
- ¼ cup softened butter
- ½ cup powdered sweetener
- ½ teaspoon vanilla extract
- coconut milk or almond milk to desired consistency (about 1 tablespoon)
Low Carb Sweeteners | Keto Sweetener Conversion Chart
Nutrition
Additional Info
Notes on Nutritional Information
Nutritional information for the recipe is provided as a courtesy and is approximate only. We cannot guarantee the accuracy of the nutritional information given for any recipe on this site. Erythritol carbs are not included in carb counts as it has been shown not to impact blood sugar. Net carbs are the total carbs minus fiber.
Copyright
© LowCarbYum.com - Unauthorized use of this material without written permission is strictly prohibited unless for personal offline purposes. Single photos may be used, provided that full credit is given to LowCarbYum.com along with a link back to the original content.
First published on April 15, 2015. Updated on January 19, 2021 with clearer images and recipe information.
Denise
Thank you so much for including oven directions. I'm going to try it in my air fryer too. We eliminated our microwave years ago and I really appreciate work-arounds.
Judy M
Hi Lisa, I’d like to try making this with stevia drops. I can’t eat Erythritol.
Do you think this would work with stevia drops,? Shoukd I add more of something else for the bulk? Thank you.
Lisa MarcAurele
It does work with liquid sweeter. You'll just need to adjust it to taste.
Judy M
Thank you so much Lisa! So many recipes don’t work no liquid sweetener because there isn’t any bulk. This will be a big treat for sure. Thank you for your reply
Natasha Siwik
I tried but it ended up very eggy tasting which the vanilla did not hide. Thanks for the efforts in posting this recipe though! It’s appreciated.
Sharon
I LOVE this cake! It is amazing. I have made it 3 times now. The thing is, it is so versatile. Made as is the first time. Next time I made a coconut cake using coconut extract. The third time I made a strawberry cake using strawberry extract. Next I might have to try lemon and maybe chocolate. I have been adding about 1 Tbsp of cream cheese to the frosting as well. This is definitely a keeper. Thanks for sharing!
Jennifer
Do you need to refrigerate the keto birthday cake in minutes, if you are not eating it right away?
Lisa MarcAurele
I keep it in the refrigerator.
Wilma
I’m following the recipe, but the batter will not rise. What am I doing wrong?
Lisa MarcAurele
The rise comes from baking powder and eggs.
Lauren
I am confused by the servings. The ingredients above are for one layer or two? Am I supposed to use these ingredients to make one layer and then do it again for another layer? So in total I would be using: (for two layers)
4 tablespoons almond flour
2tablespoon coconut flour
1/2 teaspoon baking powder
dash salt
2 tablespoon coconut oil melted
4 tablespoons plus 2 teaspoon almond milk
2 egg
2 tablespoons low carb sugar substitute
1 teaspoon vanilla extract
Lisa MarcAurele
I need to fix the recipe. The ingredients make one layer. For two layers you will need double the ingredients. Sorry about the confusion.
Gennesa
I don’t use a microwave, so wondering if I could cook in a toaster oven, and if so, how long would I cook it at 350? 10 minutes? Thx!
Lisa MarcAurele
I'd start checking it around 10 minutes for doneness.
Carmella
I made this for my son and his heart friend and they really didn’t like it. Too eggy for them. I tried it and didn’t like it either. I ended up making a new mug cake from a pumpkin recipe and they both loved it. I don’t know, maybe too much vanilla for us.
Brenda
Carmella I read your comment and I’m having trouble finding a recipe I can eat too. Would you mind sharing the pumpkin recipe please? Thanks Brenda
Susan
Not my favorite. Cake has very little flavor and frosting just tastes like Erythritol. I’ll be tweaking it and probably adding liquid stevia to balance out the Erythritol in both the cake and the frosting. Looked mighty pretty though.
MyDarlin
I used oat flour for the coconut, reduced the milk a bit bc I used Skinny Syrups Birthday Cake flavor. It made three mini waffles. Delicious!