1. Spray a medium microwave-safe bowl with non-stick spray and set aside.
2. In a mixing bowl, combine the butter, sugar, egg, vanilla extract, and milk; blend together.
3. Combine the flour, cocoa powder, baking powder and salt; blend into the mixture until smooth. Pour into greased bowl.
4. Cover and cook in the microwave on high for 2 to 2 1/2 minutes, or until cake springs back when touched.
5. Since all microwaves cook differently, adjust the cooking time to accommodate your machine.
6. To serve, let the cake cool five minutes, then cover the bowl with a plate and turn both bowl and plate upside down so the cake falls onto the plate.

Serves:4
Calories:869