Step 1

In a measuring cup, combine the flour, sugar, baking powder, and salt. Add milk, butter, and vanilla while whisking. Pour the dough into a coffee cup.

Step 2

Microwave the mug cake on high for 1 to 2 minutes or until cake is well inflated.

Step 3

In another small bowl, mix cream cheese and water. Microwave frosting till liquid, about 40 seconds.

Step 4

Pour icing over the cake and sprinkle with cinnamon. Serve.