12 egg whites
1 1/2 tsp. cream of tartar
1/4 tsp. salt
1 1/2 c. sugar
1 c. sifted cake flour
1 1/2 tsp. vanilla extract

Beat egg whites in a large mixing bowl at high speed with an electric mixer until foamy. Add cream of tartar and salt; beat until soft peaks form. Add sugar, 2 tablespoons at a time, beating until stiff peaks form and sugar dissolves. Sprinkle flour over egg white mixture, 1/4 cup at a time, folding in after each addition. Fold in vanilla. Pour batter into an ungreased 10-inch tube pan, spreading batter evenly in pan. Cut through batter with knife to remove air bubbles.

Bake at 375°F for 30 to 35 minutes. Invert tube pan until cool.