Sponge Cake or Banana-Nut Cake

Using 2 large mixing bowls, separate 7 of the 9 eggs. Yolks in 1 bowl, whites in the other.

Into the bowl with the egg yolks, add the 2 remaining whole eggs. Beat until foamy. Gradually add the sugar. Beat until light and lemon-colored. Add potato starch alternately with the juice of the orange and the juice of the lemon.

With an electric mixer and clean beaters, beat egg whites until stiff and dry.

Carefully fold the yolk mixture into the stiffly beaten egg whites. Pour batter into an ungreased 10-inch tube pan.

Bake at 325 degrees for 1 hour and 10 minutes (70 minutes total).

Invert tube pan. Cool for at least 1 hour.

Banana-Nut Cake Variation: Omit orange juice. Increase lemon juice to the juice of 2 lemons. Add 2 mashed ripe bananas and 1/2 cup chopped nuts to batter.