Sponge Cake
["1 1/4 c. sifted Pillsbury Sno Sheen cake flour", "1 c. sugar", "1/2 tsp. double-acting baking powder", "3/4 c. egg whites (6 medium)", "1/2 tsp. salt", "1 tsp. cream of tartar", "1/2 c. additional sugar", "1/2 c. egg yolks (6 medium)", "1/4 c. cold water", "1 tsp. vanilla", "1 tsp. lemon or almond extract"]
["Sift together flour, 1 cup sugar and baking powder into small mixer bowl.", "Measure egg whites, salt and cream of tartar into large mixing bowl.", "Beat with electric mixer at high speed until very soft mounds begin to form.", "Beat 1/2 cup additional sugar into egg whites, a tablespoon at a time.", "Continue beating until very stiff, straight peaks form when beater is raised.", "Do not underbeat."]
["flour", "sugar", "double-acting baking powder", "egg whites", "salt", "cream of tartar", "additional sugar", "egg yolks", "cold water", "vanilla", "lemon"]