Step 1

Spray a microwave-safe mug with nonstick spray. Add powdered peanut butter and baking powder. Mix well.

Step 2

Add all remaining ingredients. Microwave for 1 minute, or until mostly set.

Step 3

If you like, immediately run a knife along the edges to help separate the cake from its mug. Firmly place a plate over the mug, and flip so that the plate is on the bottom. Gently shake mug to release cake onto the plate.