Healthy Recipes Blog

  • ♥️ Saved Recipes
  • About
  • Newsletter
  • Index
menu icon
go to homepage
  • ♥️ Saved Recipes
  • About
  • Newsletter
  • Index
subscribe
search icon
Homepage link
  • ♥️ Saved Recipes
  • About
  • Newsletter
  • Index
×
Home » Desserts » Keto Peanut Butter Mug Cake

Keto Peanut Butter Mug Cake

A photo of Vered DeLeeuw.
by Vered DeLeeuwUpdated Jun 30, 2025
6 Comments
5 from 8 votes

Jump to Recipe Review Recipe

This flourless cake is amazing. It's ready in five minutes and makes the perfect keto breakfast or snack. Add a few chocolate chips or whipped cream, and it becomes an indulgent dessert!

Keto peanut butter mug cake is topped with whipped cream.

I've been working on this cake for a while now. It's a simple cake with four ingredients, but since nut butters greatly vary in texture, it wasn't that easy to get the ratios right. It took several tries, but I eventually reached perfection - a delicious, gooey, and moist cake with just the right level of sweetness.

Ingredients

The ingredients needed to make a keto peanut butter mug cake.

See the recipe card for exact measurements. Here are my comments on the ingredients.

  • Peanut butter: I use natural creamy peanut butter. I typically use Trader Joe's peanut butter, which contains peanuts and salt.
  • Egg: I use large eggs in most of my recipes, including this one.
  • Sweetener: I use stevia. You can use a granulated sweetener instead.
  • Baking soda: You can replace it with a teaspoon of baking powder (gluten-free if needed).
  • Optional: Mix a tablespoon of mini chocolate chips into the batter before microwaving.

Instructions

The detailed instructions and step-by-step photos are included in the recipe card. Here's a quick overview.

Mix the peanut butter and egg in a mug or ramekin until completely incorporated.

Peanut butter and egg in a ramekin.

Mix in the sweetener and baking soda.

Mixing water into the batter.

Microwave the cake for 30 seconds. If needed, microwave it for 10 more seconds. Don't overcook it! If you wish, top it with keto whipped cream or chocolate whipped cream before serving.

Topping the cake with whipped cream.

5 stars rating. I just tried this and it turned out fantastic! It's so moist and tasty! I used 3 pumps of skinny girl pumpkin praline syrup instead of the liquid stevia. I'm definitely going to make this often!
Flkitten
Read more comments

Recipe Tips

Based on my attempts, I have a few pointers for you. The gist is that because this recipe relies on peanut butter and microwave baking, the results will vary depending on what peanut butter you use and your microwave.

  1. Use a freshly opened jar of natural peanut butter and stir it well. If you opt for a half-used jar, the peanut butter might be too dry.
  2. I don't add salt because my peanut butter is salted. If your peanut butter contains just peanuts, add a pinch of salt.
  3. Microwaves vary. I always start with 30 seconds, check the cake, then usually add 10 more seconds. By then, the edges are puffed and the center is still gooey - and that's exactly how I like it.
  4. You should mix the peanut butter and egg thoroughly until the mixture is completely smooth and uniform. If the batter is very thick and sticky, add a tablespoon of water. This makes mixing much easier. The photo below shows you what the batter should look like - smooth, shiny, and not too sticky.
Mixing stevia into the batter.

Recipe FAQs

Do mug cakes really work?

Yes! I was suspicious, too, when I first started making them. But they do work, and they produce results that are very close to a real cake crumb - tender, fluffy, and sweet. The photo below shows you the beautiful, tender crumb of this cake.

A spoon showing off the cake's tender crumb.

What type of mug should I use?

You have some flexibility here. I have made this cake in several dishes. A small and tall 10-ounce mug, a wide 15-ounce mug, and a 3.5-inch-wide ramekin (as shown in the video and the photos on this page).

They all worked, and there wasn't much of a difference. Except that with the ramekin, I was worried there for a moment that the batter might overflow! But it didn't. You can always place your mug on a microwave-safe plate to catch possible spills.

Can I use almond butter?

Yes. You can use natural almond butter. If you do, I recommend adding ¼ teaspoon of almond extract to enhance the flavor.

How long can I keep this cake?

You can store the cooled leftovers in the fridge for up to 4 days (provided you didn't top the cake with whipped cream). You can leave the cake in the mug and wrap the mug in two layers of cling wrap.

You can also freeze this cake. Let it cool completely on a cooling rack, then wrap the mug with plastic wrap, followed by a layer of foil. Freeze the cake for up to three months. You can defrost it in the microwave after removing the layers of foil and cling wrap.

Recipe Card

Keto peanut butter mug cake is topped with whipped cream.
5 from 8 votes
Save this RecipeSaved! Rate this Recipe Print Recipe

Keto Peanut Butter Mug Cake

This flourless cake is amazing. It's ready in five minutes and makes the perfect keto breakfast or snack.
Prep Time5 minutes mins
Cook Time1 minute min
Total Time6 minutes mins
Course: Breakfast
Cuisine: American
Diet: Gluten Free
Servings: 1 serving
Calories: 472kcal
Author: Vered DeLeeuw
Prevent your screen from going dark

Video

Ingredients

  • ¼ cup natural creamy peanut butter - only ground peanuts and salt
  • 1 large egg
  • ½ teaspoon stevia glycerite - equals 2 tablespoons of sugar
  • ¼ teaspoon baking soda

Instructions

  • In a medium mug or a large ramekin, mix the peanut butter and egg until completely incorporated. Check especially on the bottom to make sure there is no peanut butter residue.  
    Peanut butter and egg in a ramekin.
  • If the batter seems very thick, sticky, and stubborn, add a tablespoon of water and keep mixing until completely smooth. 
    Mixing water into the batter.
  • Mix in the stevia, then the baking soda. Mix well. 
    Mixing stevia into the batter.
  • Microwave the cake for 30 seconds. Check it - if it looks very wet, add 10 more seconds. I usually stop at this point - the edges are puffed and done, but the center is still gooey. That's how I like it! 
    The cake is ready.
  • Enjoy the cake as is, or top it with a dollop of whipped cream for a truly rich experience. 
    Topping the cake with whipped cream.

Notes

  • Use a freshly opened jar of natural peanut butter and stir it well. If you use a half-used jar, the peanut butter might be too dry.
  • Go by how the mixture looks and feels. It should be smooth, shiny, and not too thick. If it's sticky and difficult to mix, add an extra tablespoon of water.
  • I don't add salt because my peanut butter is salted. If your peanut butter contains just peanuts, add a pinch of salt.
  • I have made this cake in several dishes. A small and tall 10-ounce mug, a wide 15-ounce mug, and a 3.5-inch-wide ramekin (as shown in the video and the photos on this page). They all worked, and there wasn't much of a difference. Except that with the ramekin, I was worried there for a moment that the batter might overflow! But it didn't. You can always place your mug on a microwave-safe plate to catch possible spills.
  • Occasionally, baking soda can cause a reaction in baked goods that results in an ammonia smell. If you're concerned about it happening, use 1 teaspoon of baking powder (gluten-free if needed) instead of baking soda. Make sure the baking powder is fresh and not expired.
  • You can store the cooled leftovers in the fridge for up to 4 days (provided you didn't top the cake with whipped cream). You can leave the cake in the mug and wrap the mug in two layers of cling wrap.
  • You can also freeze this cake. Let it cool completely on a cooling rack, then wrap the mug with plastic wrap, followed by a layer of foil. Freeze the cake for up to three months. You can defrost it in the microwave after removing the layers of foil and cling wrap.

Nutrition per Serving

Serving: 1 cake | Calories: 472 kcal | Carbohydrates: 14 g | Protein: 22 g | Fat: 35 g | Saturated Fat: 5 g | Sodium: 465 mg | Fiber: 6 g | Sugar: 4 g

Save this Recipe!

We'll email this recipe to you, so you can come back to it later!

We will also add you to our weekly newsletter. Unsubscribe anytime. See healthyrecipesblogs.com/privacy/ to learn how we use your email.

Disclaimers

Most recipes are low-carb and gluten-free, but some are not. Recommended and linked products are not guaranteed to be gluten-free. Nutrition info is approximate. Please verify it independently. The carb count excludes non-nutritive sweeteners. Please read these Terms of Use before using any of my recipes.

Share this Recipe

2.3K shares

More Desserts

  • Cottage cheese chocolate mousse is served in dessert glasses with dessert spoons.
    Cottage Cheese Chocolate Mousse
  • Keto mug cake is served on a white plate with a fork.
    Keto Mug Cake
  • A stack of three keto brownies.
    Keto Brownies
  • Keto cookie dough is served in a white bowl.
    Keto Cookie Dough

Comments

    Leave a Comment or Ask a Question: Cancel reply

    If you had any issues, I would love to help you troubleshoot before you rate the recipe. Have a photo? Email it to healthyrecipesblog@gmail.com and I might post it!

    Your email address will not be published. Required fields are marked *.


    Recipe Rating




  1. maria says

    January 08, 2025 at 12:39 pm

    5 stars
    Surprised but really good. I used cashew, almond, peanut butter. Thank you!!

    Reply
    • Vered DeLeeuw says

      January 08, 2025 at 7:26 pm

      You're very welcome, Maria!

  2. Flkitten says

    October 20, 2023 at 2:02 pm

    5 stars
    I just tried this and it turned out fantastic! it's so moist and tasty! I used 3 pumps of skinny girl pumpkin praline syrup instead of the liquid stevia. I'm definitely going to make this often!

    Reply
    • Vered DeLeeuw says

      October 20, 2023 at 3:49 pm

      I'm so glad you enjoyed this mug cake! Thank you for leaving a comment.

    • MCC says

      February 10, 2024 at 12:38 pm

      I use vanilla extract, allulose sweetener and a little swerve brown sugar, a tablespoon of heavy whipping cream for moisture, and mix in a few Reese’s peanut butter morsels.

    • Vered DeLeeuw says

      February 10, 2024 at 1:43 pm

      Sounds great! Thanks for sharing your version.

A photo of Vered DeLeeuw.

Welcome!

Healthy Recipes Blog was founded in 2011 by Vered DeLeeuw. It features real food recipes with a focus on low-carb and gluten-free ingredients. All recipes are nutritionally reviewed by a Registered Dietitian. Contact us at HealthyRecipesBlog@gmail.com.

Start Here

Popular Recipes

  • Korean ground beef is served in a bowl with chopsticks.
    Korean Ground Beef
  • Sautéed shrimp are served on a white plate with a napkin.
    Sautéed Shrimp
  • Baked pork chops are served in a cast-iron skillet.
    Baked Pork Chops
  • Turkey burgers are served with lettuce and sliced tomatoes.
    Turkey Burgers
  • Three cauliflower steaks are served on a white plate.
    Cauliflower Steak
  • Baked cod is served on top of asparagus.
    Baked Cod

Footer

As seen on:

Logos of media outlets that featured Healthy Recipes Blog.
↑ back to top

Explore

  • Recipe Index
  • About
  • Newsletter

Terms

  • Privacy Policy
  • Terms
  • Accessibility

Copyright © 2011-2025 • The information on this website has not been evaluated by the FDA and is not intended to diagnose, treat, prevent, or cure any disease • All recipes were tested, photographed, and written by a human • Contact us at HealthyRecipesBlog [at] gmail.com.

Rate This Recipe

Your vote:




Please comment below. Your email won't be published. If you had any issues, I would appreciate the opportunity to troubleshoot before you rate. Have a photo? Email it to healthyrecipesblog@gmail.com, and I might post it!

Such a great recipe. Thanks!
This was so good. I will definitely make it again.
Loved it! Thank you so much.

Or write in your own words:

A rating is required
A name is required
An email is required