White Part:
1/2 cup sifted cake flour
1/2 cup sifted powdered sugar
Six egg whites
1/2 teaspoon cream of tartar
1/2 teaspoon vanilla
1/8 teaspoon salt
1/2 cup granulated sugar
Yellow Part:
3/4 cup sifted cake flour
3/4 teaspoon baking powder
Six egg yolks
2 tablespoons lemon juice
1 tablespoon cold water
1/2 cup granulated sugar
Powdered sugar
Directions, White Part:
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:
Sift 3/4-cup cake flour and baking powder together three times. Beat yolks with juice and water until thick, five to seven 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 for 35 to 40 minutes. Invert and cool.
Dust cake with powdered sugar.
Bake for approximately 30 minutes.