Step 1

Mist a large mug with oil spray. Add all of the ingredients and mix together so they're well-combined.

Step 2

Microwave for 2½ to 3 minutes. (Start with 2½ minutes and check for doneness. If you'd like it firmer, place back into microwave for another 30 seconds). Let cool.

Step 3

While the cake is in the microwave, make the frosting by mixing the cream cheese and maple syrup until well-blended. Spread over carrot cake, garnish with chopped walnuts, if using, and dig in.