8 Large Eggs, Separated
1 1/4 Cup Sugar
7/8 Cup Cake Meal \
3/8 Cup Potato Starch / = 1 1/4 Cups
1/4 Cup Orange Juice
1 TSP Vanilla (Optional)
Beat Egg Yolks until frothy. Add 1 Cup of sugar. Continue beating at high speed until very thick and lemon colored, about 2 minutes. Add Vanilla (optional).
Add Cake Meal/starch to egg yolks with juice. Mash with beater until just blended. Beat at medium speed until smooth, about 4 minutes.
Clean beaters thoroughly.
Whip egg whites at highest speed until soft peaks begin to form. Slowly add remaining 1/4 cup sugar while beating. Continue beating until stiff. Keep scraping sides and bottom of bowl to be sure that whipped whites are uniform. Whites will look smooth, shiny, and hold stiff when divided with spatula.
Carefully fold whites into yolk mixture until just uniform and completely incorporated.
Turn folded mixture into tube pan and smooth top with spatula.
Bake 1 Hour at 325 degrees. Then touch lightly on top. Keep baking for additional five minute intervals until cake won't retain finger impression when touched lightly at center of ring top, about 1 hour and 10 minutes total.
Variations:
Substitute almond extract, amaretto, or other flavoring for vanilla.
Substitute apple juice for orange juice.
For Chocolate sponge: Water instead of juice, 1/3 cup cocoa for 1/3 cup of the cake meal.
Jeff Bienenfeld 1987 (originated 1982, corrected 1984)