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).
Add the wet ingredients and use a fork or a small whisk to mix until the batter is smooth.
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.
This nutritional information has been automatically calculated, and as such, may be incomplete or inaccurate. Please reference the specific ingredients you use for the most accurate nutritional information.