Yellow Layer Cake
["1 c. butter or margarine", "1/2 c. shortening", "2 2/3 c. sugar", "5 eggs", "2 tsp. vanilla", "3 c. sifted all-purpose flour", "1 tsp. baking powder", "1/2 tsp. salt", "1 c. milk"]
["Preheat oven to 350\u00b0.", "Grease and flour three 9-inch round or two 9-inch square cake pans."]
["butter", "shortening", "sugar", "eggs", "vanilla", "flour", "baking powder", "salt", "milk"]