Chocolate Peanut Butter Keto Mug Cake | Easy, Low Carb, REESE'S Mug Cake For Keto

A fork about to take a piece of chocolate and peanut butter cake out of a mug.

5 from 5 reviews

My family is obsessed with this chocolate peanut butter keto mug cake. It's reminiscent of a Reese’s candy but in delicious lava cake form. Honestly, it’s pretty tough to believe this dessert is totally sugar free and keto friendly! It’s just SO GOOD. And what makes it even better is that the whole thing takes just 1 minute in the microwave.


1 Large Egg

½ Tbsp. (7g) Unsalted Butter, Melted

¼ Tsp. Pure Vanilla Extract

¼ Cup (28g) Blanched Almond Flour

2 Heaping tbsps (20g) Confectioners Swerve

1 Tbsp. (5g) Unsweetened Cocoa Powder

½ Tsp. Baking Powder

Pinch of Salt

Peanut Butter Filling:

1½ Tbsps. (24g) Natural No Sugar Added Peanut Butter

½ Tbsp. (7g) Unsalted Butter

2 Tsps. (6g) Confectioners Swerve

Pinch of Salt


  1. In a large measuring cup add all of the liquid ingredients, and whisk them until combined.
  2. Now add the dry ingredients, and mix until they’re well incorporated with the wet ingredients.
  3. Next, coat an 8oz (240mL) ramekin with baking spray, and add about 80% of the batter to the ramekin.
  4. Cook for 30 seconds, and let cool.
  5. In a small dish start making the peanut butter filling.
  6. To do this, add the peanut butter and the butter to the dish, and microwave for about 15 seconds - or until the butter has melted.
  7. Once it has, mix the two until they’re combined.
  8. Now, add, & stir in, the Swerve and the salt.
  9. Once they’re combined, use a tablespoon to form a small indent in the middle of the mug cake, and add the peanut butter filling to it.
  10. When all of the peanut butter has been added, pour the rest of the chocolate cake batter around the sides of the mug cake - only lightly cover the peanut butter with cake batter.
  11. Now microwave in 15 second intervals until the cake is just SLIGHTLY UNDERCOOKED.
  12. For me, this usually takes about 3 intervals.
  13. Once the cake has cooked to that point, remove it from the microwave, and enjoy!


Microwave times may vary depending on the power of your microwave. Mine is 1100 Watts, and the times are based off of a microwave of that power. Adjust accordingly.

Mug cakes are always best SLIGHTLY UNDERCOOKED, they will continue to cook as they cool.


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