Notes: In Jewish homes, a true cook is one who can turn out Passover desserts no easy feat when youre forbidden from using any leavening or traditional flour. This sponge cake takes some effort (separating 10 eggs, beating the whites and yolks separately and folding by hand), but the result is a lofty, light, citrus-flavored cake ready for whipped cream and berries one night and as the base for trifle the next.
10 eggs, separated
1½ cups sugar
1 teaspoon salt
Grated rind of an orange
Juice of ½ a lemon
½ cup orange juice
½ cup potato starch
½ cup Passover cake meal
Preheat oven to 325 F. Have an ungreased angel-food cake pan at hand.
In a large bowl, beat egg whites until stiff. Gradually add ¾ cup of the sugar until smooth and glossy.
In another bowl, beat yolks until thick. Slowly add in the remaining sugar until mixture forms a thick ribbon. Add juices and rind on low speed until combined.
Sift starch and cake meal together three times. Gradually add to the egg yolk mixture. Fold in the whites by hand until no streaks appear.
Pour into pan and bake for 1 hour and 15 minutes or until the center of the cake springs back when lightly touched.