Step 1

Whisk together all of the dry ingredients in a medium microwave safe mug (I used a 4-ounce tea cup in the photos above and it just reaches the very top, so I'd recommend using 4-ounces or larger).

Step 2

Add the wet ingredients and use a fork or a small whisk to mix until the batter is smooth.

Step 3

Cook in the microwave for 1 minute. If the cake is not done, heat an additional 15 seconds. Sprinkle with powdered sugar and serve immediately.