Hot Milk Sponge Cake
["4 egg yolks, beaten", "4 egg whites", "2 c. sugar", "1 c. hot milk with butter like walnut", "2 tsp. baking powder", "1 tsp. vanilla", "2 c. flour"]
["Beat egg whites until stiff and fold in last.", "Bake until a toothpick comes out clean.", "Bake at 350\u00b0."]
["egg yolks", "egg whites", "sugar", "milk", "baking powder", "vanilla", "flour"]