Peanut Butter Mug Cake

This peanut butter mug cake is soft, fluffy, and ready in minutes. Made with simple ingredients and no flour, it’s the perfect quick dessert.

Course Breakfast

Cuisine American

Diet Gluten Free

Prep Time 5

Cook Time 1

Total Time 6

Servings serving

Calories 472kcal

¼ cup peanut butter natural, creamy; only ground peanuts and salt
1 large egg
Granulated sweetener of choice to equal 2 tablespoons of sugar; I use ½ teaspoon of stevia glycerite
¼ teaspoon baking soda or ½ teaspoon baking powder

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.
If the batter seems very thick, sticky, and stubborn, add a tablespoon of water and keep mixing until completely smooth.
Mix in the sweetener, then the baking soda. Mix well.
Place the mug on a microwave-safe plate to catch any spills. 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! See the notes section below for more tips about timing.
Enjoy the cake as is, or top it with a dollop of whipped cream for a truly rich experience.

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.
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 4-inch-wide ramekin (as shown in the video and the photos on this page). They all worked.
Make-ahead: You can mix the batter the night before, wrap the mug in cling wrap, and refrigerate. In the morning, remove the plastic wrap and microwave the cake.
See the article above the recipe card for a lighter version of this cake, made with powdered peanut butter.
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.