Mug Coffee Cake

Mug Coffee Cake
2 T butter, softened, separated
2 T + 2 t sugar, separated
1 egg white
2 T sour cream
1/2 t vanilla
1/8 t baking powder
6 T flour, separated
2 t cinnamon, separated
1 T brown sugar

1. Cream 1 tablespoon butter and 2 tablespoons sugar in a mug; add egg white, sour cream, and vanilla.
2. Stir in baking powder and 4 tablespoons flour; swirl in 2 teaspoons sugar and 1 teaspoon cinnamon.
3. In a small bowl, mix remaining tablespoon butter, 2 tablespoons flour, brown sugar, and 1 teaspoon cinnamon; sprinkle over cake mix in mug.
4. Microwave, on high, for about 1 minute and 20 seconds.