Whoopee Pies
["1/2 c. margarine", "1 c. sugar", "1 c. milk", "1 tsp. vanilla", "2 c. flour", "1 tsp. baking powder", "1 tsp. baking soda", "1/2 tsp. salt", "5 Tbsp. cocoa", "2 egg yolks"]
["Cream, the margarine and sugar.", "Add egg yolks.", "Sift dry ingredients and add, alternating with milk and vanilla.", "Drop on greased cookie sheet by tablespoonful.", "Bake at 350\u00b0 for 10 minutes.", "When cool, put together with the following filling."]
["margarine", "sugar", "milk", "vanilla", "flour", "baking powder", "baking soda", "salt", "cocoa", "egg yolks"]