1/2 c Sifted cake flour
1/2 c Sifted powdered sugar
6 Egg whites
1/2 ts Cream of tartar
1/2 ts Vanilla
1/8 ts Salt
1/2 c Granulated sugar
3/4 c Sifted cake flour
3/4 ts Baking powder
6 Egg yolks
2 tb Lemon juice
1 tb Cold water
1/2 c Granulated sugar

Powdered sugar
White part of cake: Sift 1/2 cup cake flour and 1/2 cup powdered sugar together three times. Beat egg whites till frothy; add cream of tartar, vanilla, and salt. Beat till soft peaks form. Gradually beat in 1/2 cup granulated sugar. Sift a fourth of the flour mixture at a time over top; fold in.

Yellow part of cake: Sift 3/4 cup cake flour and baking powder together three times. Beat yolks with juice and water until thick, 5 to 7 minutes; gradually beat in 1/2 cup granulated sugar. Sift a fourth of the flour mixture at a time over top; fold in.

Alternately spoon yellow and white mixtures into an ungreased 9- or 10-inch tube pan. Bake at 375 degrees F for 35 to 40 minutes. Invert and cool. Dust cake with powdered sugar.