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3-Ingredient Keto Mug Cake (Flourless)

4.97 from 219 votes
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This recipe may contain Amazon or other affiliate links. As an Amazon Associate I earn from qualifying purchases.

An easy flourless 3-Ingredients Keto Mug Cake recipe to fix a quick sweet craving in no time with only 3 basic pantry ingredients.

Plus, this mug cake contains only 6.5 grams of net carbs per serving, and it’s naturally gluten-free and dairy-free.

How To Make A 3-Ingredients Flourless Keto Mug Cake

A 3-ingredient Keto Mug Cake is a single-serving cake, easy, quick, and baked in the microwave in 90 seconds.


All you need to make this simple flourless keto mug cake recipe are:

  • Nut butter – I used natural peanut butter, but natural almond butter works as well.
  • Large egg at room temperature.
  • Stevia-sweetened cocoa powder – I used keto drinking chocolate mix made of unsweetened cocoa powder and erythritol. Some popular brands I love are Lakanto or Avalanche.

Note that you use unsweetened cocoa powder in this recipe. The keto mug cake is unsweetened because natural peanut butter has no sweetener added.

So to make the mug cake sweet, you will need a fourth ingredient, like 1 1/2 tablespoon erythritol or stevia drops.

3 ingredients Flourless Mug Cake

Making The Batter

First, make sure you stir very well the peanut butter in its jar.

This recombines the oily layer that often shows on top of fresh jars and dries up the spread under it.

Next, beat the egg and peanut butter together.

Make sure both ingredients are at room temperature and that your spread is creamy, drippy not dry in its jar.

If you are using a dry spread, the mug cake will be crumbly and not good.

Finally, stir in cocoa powder and a touch of baking powder only if you prefer a fluffy keto mug cake.

I personally like the easy 3-ingredient version. It tastes like a brownie.

The batter of this keto mug cake should be relatively liquid, not thick or dry.


Finally, transfer the batter into an 8-once coffee mug and microwave for 60-90 seconds.

Start microwaving for 60 seconds at 900W, then add 10 seconds burst until cake is set on top.

Cool the mug cake down for 30 seconds in the mug before eating.

3 ingredients Chocolate Keto Mug Cake

Serving Ideas

Serve your keto mug cake topped with:

  • Sugar-free keto chocolate chips
  • Drizzle natural peanut butter
  • Unsweetened whipped cream

Tips and Troubleshooting

If your batter is too dry, this can happen if your peanut butter is not fresh from the jar or you used a smaller egg than mine.

Then, stir in 1 teaspoon of melted butter or coconut oil.

You can also stir in 1 teaspoon almond milk.

Keto-Baking-Guide-Best-Bread-Recipes Carine Grab my Keto Meal Plans! Use one of my many keto meal plans to reach your health goals!

Storage Instructions

You can’t store a baked keto mug cake simply because microwave baking dries out food super fast. As a result, cakes are good to eat for only 30 minutes after baking.

After that time, their texture becomes crumbly and extra dry.

However, it’s a great keto-friendly recipe to make ahead. Simply whisk egg, spread, and almond flour the day before. Store in your mug, wrap top with plastic wrap, and pop in the fridge.

The next day, microwave as recommended in the recipe.

Taste and texture

This 3-ingredient mug cake tastes like a brownie-like chocolate cake. I love to top it with sugar-free dark chocolate chips to add an extra smooth melted chocolate texture to the crumb.

Depending on the cooking time you apply, the cake can be moister or dryer.

I always recommend microwaving the mug cake for 60 seconds and adding 10 seconds burst until the texture looks like your favorite keto cake recipe.

3 ingredients Flourless Mug Cake

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Allergy Swaps

If you can’t find some of the ingredients in this recipe in your grocery store, you can use another simple swap like:

  • Natural peanut butter swaps – drippy Almond butter, sunflower seed butter, cashew butter.
  • Stevia sweetened cocoa powder – replace with 1/2 tablespoon of unsweetened cocoa powder (or cacao powder) combined with 1 to 1 1/2 tablespoon erythritol.

More Keto Mug Cake Recipes

I love to create keto mug cake recipes to fix my sweet tooth on my keto diet and minimize carbs for breakfast!

Below I listed my favorite other keto low-carb mug cake recipes for you to try.

Have you made this low-carb chocolate mug cake with 3 ingredients? Share a review or comment below,

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Leave a comment below or head to our Facebook page for tips, our Instagram page for inspiration, our Pinterest for saving recipes, and Flipboard to get all the new ones!

3 ingredients Keto Mug Cake

3-Ingredient Keto Mug Cake

6.5gNet Carbs
A delicious fudgy chocolate Keto Mug Cake made with 3 simple ingredients.
Prep: 2 minutes
Cook: 2 minutes
Total: 4 minutes
Yield: 1 mug cake
Serving Size: 1 mug cake
4.97 from 219 votes


Optional – for a fluffier mug cake

This recipe may contain Amazon or other affiliate links. As an Amazon Associate I earn from qualifying purchases.


  • In a small bowl, whisk egg and natural peanut butter. Beat until it is consistent and it looks like melted peanut butter. You shouldn't see egg white pieces.
  • Stir in sugar-free drinking chocolate powder and a pinch of baking powder for a fluffier cake, or, if you used unsweetened cocoa powder, use 1/2 tablespoons cocoa + 1 1/2 tablespoons erythritol.
  • Transfer the batter into a tall 8-ounce coffee mug.
  • Microwave for 90 seconds at 900W until the cake is set.
  • Serve with a dollop of unsweetened whipped cream or sugar-free chocolate chips.

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Nutrition1 mug cake
Yield: 1 mug cake


Serving: 1 mug cakeCalories: 272.1 kcal (14%)Carbohydrates: 10.1 g (3%)Fiber: 3.6 g (15%)Net Carbs: 6.5 gProtein: 15.3 g (31%)Fat: 21.6 g (33%)Saturated Fat: 5.3 g (33%)Polyunsaturated Fat: 5.5 gMonounsaturated Fat: 9.8 gTrans Fat: 0.1 gCholesterol: 186 mg (62%)Sodium: 430.9 mg (19%)Potassium: 353.3 mg (10%)Sugar: 3.2 g (4%)Vitamin A: 270 IU (5%)Vitamin B12: 0.5 µg (8%)Vitamin D: 1 µg (7%)Calcium: 165.7 mg (17%)Iron: 2.4 mg (13%)Magnesium: 80.8 mg (20%)Zinc: 1.9 mg (13%)
Carine Claudepierre

About The Author

Carine Claudepierre

Hi, I'm Carine, the food blogger, author, recipe developer, published author of a cookbook and many ebooks, and founder of Sweet As Honey.

I have an Accredited Certificate in Nutrition and Wellness obtained in 2014 from Well College Global (formerly Cadence Health). I'm passionate about sharing all my easy and tasty recipes that are both delicious and healthy. My expertise in the field comes from my background in chemistry and years of following a keto low-carb diet. But I'm also well versed in vegetarian and vegan cooking since my husband is vegan.

I now eat a more balanced diet where I alternate between keto and a Mediterranean Diet

Cooking and Baking is my true passion. In fact, I only share a small portion of my recipes on Sweet As Honey. Most of them are eaten by my husband and my two kids before I have time to take any pictures!

All my recipes are at least triple tested to make sure they work and I take pride in keeping them as accurate as possible.

Browse all my recipes with my Recipe Index.

I hope that you too find the recipes you love on Sweet As Honey!

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    7 Thoughts On 3-Ingredient Keto Mug Cake (Flourless)
    • If too dry it can be that you microwave a little bit too long or the almond flour is coarse – dry. I would recommend using ultra fine blanched almond flour and microwaving for 60 seconds to start with

  1. Hi Carine! You are my favorite kept recipe giver EVER!!! This is my second keto mug cake that I have done and OH MY LORD!!! IT IS DELICIOUS!!! I also tried the Cinnamon Roll mug cake and I even made some for both my parents and my sister and they LOVED IT!!! I will be making more mug cakes from your website! Thank you so much for these delicious mug cake recipes!!!


The recipes, instructions, and articles on this website should not be taken or used as medical advice. You must consult with your doctor before starting on a keto or low-carb diet. The nutritional data provided on Sweetashoney is to be used as indicative only.

The nutrition data is calculated using WP Recipe Maker. Net Carbs is calculated by removing the fiber and some sweeteners from the total Carbohydrates. As an example, a recipe with 10 grams of Carbs per 100 grams that contains 3 grams of erythritol and 5 grams of fiber will have a net carbs content of 2 grams. Some sweeteners are excluded because they are not metabolized.

You should always calculate the nutritional data yourself instead of relying on Sweetashoney's data. Sweetashoney and its recipes and articles are not intended to cure, prevent, diagnose, or treat any disease. Sweetashoney cannot be liable for adverse reactions or any other outcome resulting from the use of recipes or advice found on the Website.