1 c. sugar
1/3 c. water
1/3 tsp. cream of tartar

Boil slowly without stirring until syrup spins a 6-8 inch thread (240 degrees). While syrup is cooking, beat until stiff enough to hold a point: 2 egg whites (1/3 cup). Pour hot syrup very slowly in a thin stream into stiffly beaten egg whites, beating constantly. Add 1 1/2 teaspoons vanilla. Beat until frosting holds its shape. Spread on cake.