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Low-Carb Banana Mug Cake

Give this low-carb banana mug cake a try if you miss banana baked goods on a low-carb diet. Using extract instead of the fruit, it’s easy to make this tasty banana cake in a mug without all the sugar and carbs typically found in traditional recipes.

This banana nut cake in a mug is 6.3 net carbs, which makes it easy to fit into a keto diet. Enjoy this small yet filling cake with just a few ingredients and about 5 minutes!

Banana cake in a blue mug with chopped walnuts.

Low-Carb Banana Nut Cake in a Mug

A warm, freshly baked slice of banana nut bread with butter… am I the only one craving that on keto? Well, miss it no more because this tasty treat really hits the spot. Just like the mug coffee cake, this recipe is also delicious for breakfast.

You can easily control the amount of banana flavor in this mug cake. Be sure to read the notes below for important tips on using the extract. Use different nuts if you’d like and even add keto chocolate chips. Just make sure to adjust the macros if you’re closely counting.

Bowls of ingredients to make a keto banana mug cake on a table.

Banana Mug Cake Ingredients

Here’s what you need to make this recipe. The exact measurements are in the recipe card below.

  • Almond flour
  • Coconut flour
  • Erythritol
  • Baking powder
  • Cinnamon
  • Butter
  • Keto milk substitute
  • Egg
  • Banana extract
  • Walnuts

How to make keto banana mug cake

In a microwave-safe mug, dish, or ramekin, mix the almond flour, coconut flour, sweetener, baking powder, and cinnamon until well incorporated.

Dry ingredients in a light blue mug for banana cake.

Add the melted butter, milk substitute, lightly beaten egg, and banana extract. Stir until smooth, but do not over mix.

Banana mug cake batter in a mug.

Gently fold in half of the chopped walnuts to the batter and sprinkle the other half on top.

Banana cake topped with walnuts with chopped walnuts and a gold fork on the table.

Microwave for one minute and thirty seconds or until the top is opaque and cooked through.

Banana cake in a mug with a fork and chopped walnuts on the table.

Top with additional walnuts, if desired.

Fork full of banana cake raised about the rest of the cake in a light blue mug.

Be sure to serve this cake warm.

Closeup of a banana mug cake topped with walnuts.

Banana Cake in a Mug Recipe Notes and FAQ

How to add the right amount of extract.

Use 1/2 teaspoon of banana extract for a mild banana flavor. Use 1 teaspoon if you like a stronger flavor. After testing with a few different people, this truly is a matter of preference.

Overhead shot of banana cake in a mug with a bowl of chopped walnuts to the side.

Which brand of banana extract should I use?

This recipe uses McCormick banana extract. It was also tested using a candy flavoring and the results were very different. If you choose to use a different brand, please note that you might have to use more or less to get the desired flavor.

Banana cake in a blue mug with chopped walnuts.
Yield: 1 mug cake

Banana Mug Cake

Prep Time: 3 minutes
Cook Time: 2 minutes
Total Time: 5 minutes

Banana nut cake in a mug that's low-carb and ready in minutes. Net carbs for the mug cake using all the nuts: 6.3g


  • 2 Tablespoons almond flour
  • 1 Tablespoons coconut flour
  • 2 Tablespoons Erythritol, granular
  • ½ teaspoon baking powder
  • ¼ teaspoon cinnamon
  • 2 Tablespoons melted butter
  • 2 Tablespoons milk of choice
  • 1 egg, beaten
  • ½ - 1 teaspoon banana extract
  • 1 Tablespoon chopped walnuts


  1. In an 8 ounce mug, mix the almond flour, coconut flour, erythritol, baking powder, and cinnamon until well incorporated. 
  2. Add the melted butter, milk, egg, and banana extract. Stir until smooth. 
  3. Gently fold half the chopped walnuts into the batter and distribute the other half on top.
  4. Cook in the microwave for one minute and thirty seconds or until the top is opaque and cooked through. 
  5. Top with additional chopped walnuts, if desired and be sure to serve warm.


Use ½ teaspoon of extract for a more mild banana flavor and 1 teaspoon if you want a strong flavor.

You can adjust the level of sweetness by adjusting the erythritol. 

This mug cake is best served fresh and warm.

Nutrition facts calculated using Carb Manager and are not guaranteed to be 100% accurate.

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Nutrition Information:



Serving Size:

1 mug cake

Amount Per Serving: Calories: 559Total Fat: 49.9gSaturated Fat: 19.8gCholesterol: 247.5mgCarbohydrates: 44.7gNet Carbohydrates: 6.3gFiber: 10gSugar: 3.8gSugar Alcohols: 28.4gProtein: 15.9g

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Banana nut mug cake in a light blue mug.

If you try this banana mug cake I’d love to hear your thoughts in the comments below!

Terri B.

Saturday 5th of November 2022

Been looking for some KETO sweets!

Jen Soltys

Wednesday 9th of November 2022

Woo hoo! I hope you love the ones you try. :)

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