about 1/2 cup all-purpose flour (1/2 large mug)
2 to 3 tablespoons sugar
pinch salt
1 teaspoon baking powder
1 tablespoon water
1 tablespoon oil (I use canola oil)
1 tablespoon mashed banana
1 fat teaspoon peanut butter (I use crunchy)
1 teaspoon vanilla extract
1 teaspoon cinnamon, or to taste
1. Add flour, sugar, salt and baking powder to mug. Mix.
2. Add water and oil. Mix. Mixture should be liquid-ish. You may need to adjust liquids. Add banana and peanut butter. Mix.
3. Add vanilla and cinnamon. Mix. Take your mug to a microwave for 3 minutes. The cake will have a pale color once the 3 minutes are over. Fact: don't get fooled if you think that the cake is not ready yet, it is ready!
Source of recipe: I randomly put stuff inside a mug and 5 minutes later = Kaboom!'