Kirbie's Cravings

Keto Chocolate Peanut Butter Mug cake

A chocolate and peanut butter flavored mug cake studded with chocolate chips. This mug cake is flourless, gluten free, low carb and keto friendly.

Chocolate and peanut butter are one of my favorite combinations. A few months ago, I shared my 3 Ingredient Keto Peanut Butter mug cake. This cake is almost just as easy except that it adds a few more ingredients to give the cake a chocolate flavor.

Mug Cake Cooking Tips

  • Make sure that the egg is completely whisked into the batter. It can sometimes be a little hard to tell because the cocoa powder makes the batter dark. Lift your whisk a few times to check to make sure you don’t have any unmixed egg streaks.
  • This cake rises quite high during cooking so you will need to use a microwave-safe mug that can hold at least 12 oz of liquid.
  • Try to stick to standard shaped mugs. Mugs that are unusually tall/skinny or oddly shaped can cause problems with the cake cooking evenly.
  • Be careful not to overcook the cake. Because microwave cooking is so powerful, even a few seconds can make a big difference. If you feel your cake is not fully cooked, cook it a little longer at 15 second increments.

Update: Since sharing this recipe I’ve also made a Keto Blueberry Mug Cake! Or check out my Keto Lava Cake for Two.

Keto Chocolate Peanut Butter Mug Cake

Servings: 1
Prep Time: 5 minutes
Cook Time: 1 minute
Course: Dessert
Cuisine: American
This easy single serving mug cake is low carb and keto-friendly. It tastes of chocolate and peanut butter, with melty chocolate chips throughout.
4.88 from 8 votes


  • 3 tbsp creamy natural peanut butter no salt, sugar or palm oil added
  • 1/2 tbsp unsweetened cocoa powder
  • 1 large egg
  • 2 tbsp Swerve granular sweetener
  • 1 1/2 tbsp sugar free chocolate chips or dark chocolate chips


  • Add everything except chocolate chips into a microwave-safe mug that can hold at least 12 oz of liquid. Whisk with a small whisk until batter is smooth. Make sure batter is evenly mixed and egg is completely incorporated.
  • Stir in half of the chocolate chips. Sprinkle remaining on top.
  • Cook cake at full power in the microwave for about 1 minute to 1 minute 15 seconds. Cake is best eaten warm.


  •  I used an 1100 watt microwave. You may need to adjust cooking time and power if your microwave is a different wattage. 
  • Make sure that the egg is completely whisked into the batter. Because the batter is so dark, it can be hard to see unmixed egg streaks. Lift your whisk a few times to check to make sure you don't have any unmixed egg streaks.
  • For the chocolate chips, I used Lily's keto chocolate chips. You can also substitute with other sugar-free chocolate chips or chopped dark chocolate.
  • For the sugar substitute, I used Serve Granular Sweetener.* Other similar granular sugar alternatives should work.
  • *Some of the product links contained in this post are affiliate links. Much like referral codes, this means I earn a small commission if you purchase a product I referred (at no extra charge to you).
Estimated Nutrition Information is calculated with Lily's keto chocolate chips and does not include carbs from erythritol


Serving: 1cake, Calories: 412kcal, Carbohydrates: 14g, Protein: 21g, Fat: 32g, Saturated Fat: 7g, Sodium: 231mg, Fiber: 6g, Sugar: 2g, NET CARBS: 8g

The nutrition information provided are only estimates based on an online nutritional calculator. I am not a certified nutritionist. Please consult a professional nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.

Did you make this recipe?I'd love to see it! Mention @KirbieCravings and tag #kirbiecravings!

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Recipe Rating

14 comments on “Keto Chocolate Peanut Butter Mug cake”

  1. Thank you for a delicious almond and coconut free recipe!!!

  2. Enjoyed the flavor, but mine came out a little dry, cooking at 1 minute. I think I’ll try a TBSP or 2 of cream with the next attempt.

  3. OMG! Thank you for sharing! I LOVE sweets and especially chocolate cake. I have tried other mug cake recipes and they were OK but did not satisfy the full craving for something warm, moist, & chocolatey. I just made this now and was in HEAVEN! 

    It was super, super easy and the warm peanut butter gave this cake such a rich, moist flavor that tasted so decadent and rich I felt like it was not low carb at all. This is definitely my go-to desert to help me get that sweet rich fix without having to cheat on my good keto habits. Yum yum yum!

  4. I LOVE to eat, especially sweets and Oh my word, this is soooo good & exactly what I was looking for! It is almost too rich and that is saying a lot for me LOL. This is definitely my go-to dessert from now on oh, thank you!

  5. I made this tonite. I used Trader Joe’s mixed nut butter instead of pnut butter. Sprinkled a light dusting of erythritol on the top to give it just a touch more sweet. My picky eater son loved it so this recipe is a keeper. It’s so easy how could it not be! Thanks!

  6. Very good!  THank you for sharing.    I added 1/4 tsp coconut extract for a little extra flavor.

  7. This is super cute… I love it! Pinning!