Marble Cake

Divide in 2 equal parts. Pour cocoa, baking soda, and 1/4 tsp. baking powder in one. Pour rest of baking powder in vanilla. Divide into two more equal parts. Bake on 350 for 30-33 min.
 * Vanilla Cake (3/4 cup butter, 1/4 cup oil)
 * 1/4 cup cocoa powder
 * 1 1/4 tsp. baking powder
 * 1/2 tsp. baking soda