Easy Sponge Cake
["1 c. egg whites (5 to 6)", "4 egg yolks", "non nutritive sweetener equivalent to 1 c. sugar", "1 c. flour", "1 tsp. baking powder", "1/2 tsp. vanilla"]
["Preheat oven to 300\u00b0.", "Beat egg whites very stiff.", "Beat yolks until very light.", "Add half the sweetener to whites and half to yolk.", "Mix together and beat hard.", "Sift flour with baking powder.", "Fold into egg mixture.", "Add vanilla.", "Pour into angel food cake pan.", "Bake 40 minutes or until tester comes out clean."]
["egg whites", "egg yolks", "non nutritive", "flour", "baking powder", "vanilla"]