Disappearing Chocolate Cake
["1/2 c. butter", "1/2 c. shortening", "2 c. sugar", "1 tsp. vanilla", "2 eggs", "3/4 c. Hershey's cocoa", "1 3/4 c. flour", "3/4 tsp. baking powder", "3/4 tsp. baking soda", "1/8 tsp. salt", "1 3/4 c. milk"]
["Generously grease and flour two (9-inch) round cake pans. Cream butter, shortening, sugar and vanilla until fluffy.", "Blend in eggs."]
["butter", "shortening", "sugar", "vanilla", "eggs", "cocoa", "flour", "baking powder", "baking soda", "salt", "milk"]