Chocolate Peanut Butter Protein Mug Cake
Yield: 1 serving
A decadently delicious, single serve cake takes a few minutes to make and offers a hearty dose of satisfying protein too!


  • 1½ teaspoons (7ml) avocado oil or a neutral cooking oil of choice
  • 1 medium or large egg
  • 2 tablespoons (10g) cocoa powder (I use regular, not Dutch process*)
  • 1½ tablespoons (18g) granulated sugar**
  • 1 tablespoon (6g) peanut butter powder***
  • ⅛ teaspoon baking soda (lightly pack and level with a straight edge)
  • Pinch (1/16 teaspoon) kosher salt
  • 1 tablespoon mini chocolate chips (plus a few for topping, if desired)
  • Optional (but recommended!) for lava center: 1 tablespoon (16g) creamy or chunky peanut butter


  1. Add the oil to a 14- to 16-ounce microwave-safe mug. (Extra space is needed to prevent overflow; when cooking, the cake will rise a good bit before settling back down. A 12-ounce mug might work; just place on a plate to catch any overflow.)
  2. Whisk in the egg, followed by the cocoa powder, sugar, peanut butter powder, baking soda**, and salt. Stir well, making sure you get to the bottom. (Tip: If you have time, let the muffin sit on the counter for 10 minutes. This will give the dry ingredients time to absorb some of the moisture. If you can’t wait, the results will still be good.)
  3. Place the optional peanut butter in the center, right on top. It will sink down when cooking and create a molten effect. Evenly distribute the mini chips over the surface. Do not stir.
  4. Microwave on high for 45 seconds to 1 minute. (The cakes take exactly 50 seconds in my microwave.) The cake should spring back when touched, and the temperature in the center of the muffin should read between 195 – 200℉ when taken with a quick-read thermometer. If not, microwave in additional 10 second bursts.
  5. Sprinkle with a few extra chocolate chips, if using, while the muffin is still hot.
  6. Serving: Enjoy warm or at room temperature. You can eat the muffin right from the mug, or you can turn it out onto a plate or bowl. A scoop of ice cream or dollop of whipped cream may be added for extra decadence. If you turn the warm peanut butter-topped muffin out, so bottom side faces up, you’ll see the “molten” peanut butter, which sort of acts like an icing. Alternatively, you could melt peanut butter separately and drizzle it over top.


*For best results, I recommend natural cocoa powder, not Dutch process. If using Dutch process cocoa powder, however, replace the baking soda with ¼ teaspoon baking powder or use the ⅛ teaspoon baking soda and add ¼ teaspoon white or apple cider vinegar. Dutch process cocoa powder is less acidic/has higher pH, so this change is needed to create a similar rise.

**Can I use a different sweetener? Any granulated sweetener will work, so long as the quantity is the same, as the bulk is needed. So, a cup-for-cup sugar substitute would work, but a pinch of concentrated stevia would not. Brown sugar could also be used, while honey and maple syrup would make the batter too runny.

***No peanut butter powder? Finely ground almond flour works well. All-purpose flour creates an airier crumb and the perception of a drier cake. Protein powder may also be used; note that a flavored variety will slightly alter the taste (which you may like!).

Chocolate chip tips: Standard-size morsels may be used; they will sink to the bottom and create a melted chocolate layer. If you flip the cake onto a plate, it’s sort of like icing. Standard-size chips may also be dotted on top of the mug cake as soon as it’s done cooking. The hot cake will melt the bottom of the chips and make them stick. (see photos)

Mix it up:
• Feel free to substitute peanut butter, dark, or white chocolate chips. If doing so, however, roughly chop them before using to prevent the sinking mentioned above.

• For an extra hint of salty-sweet flavor, sprinkle the finished muffin with a small pinch of flaky sea salt immediately upon removing from microwave.

• Instead of the molten center, you could “frost” the finished mug cake with peanut butter.

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