Did you know that Sponge Cakes (tawrt in Yiddish, bocca di dama or pane di Spagna in Italy, blotkake in Scandinavia, biscuit in France, and sunshine cake in the Us) contains no shortening? Egg-foam cakes raise through adding air to beaten egg whites. As the eggs are beaten, numerous air bubbles are created which when heated, expand to raise the batter. The result is a light, airy texture for your cake.

Egg-foam cakes fall into two basic categories; those containing fat and those without any fat. Genoise and chiffon cakes contain fat, sponge cakes and angel food cakes contain little or no fat. Egg-foam cakes prove to be just the ticket for the fat-conscious desert lover and offer Kosher preparation during Passover.

Pre-heat oven to 325-F degrees. If desired, lightly grease bottom (not sides) of a 10-inch tube pan.

In a large mixing bowl beat egg yolks, 2 egg whites, and sugar until pale and creamy, about 10 to 15-minutes. Gently stir in juice and rind. Gently stir in potato starch or matza meal. (Stir in any additional ingredients before folding in the egg whites.)

In a separate mixing bowl beat remaining egg whites until stiff peaks, but not dry. Gently fold into yolk mixture. Pour cake batter into tube pan. Tap softly to remove large pockets of air. Place on lowest shelf of oven and bake until the cake springs back when lightly touched, about 1-hour. Invert pan onto a bottle and cool completely.

Kitchen Staff Variations:

For a Streusel-Topped Sponge Cake: Combine 2/3 cup matza meal (not cake meal), 1/2 cup light brown sugar, and 1 teaspoon cinnamon; cut in 1/4 cup butter and sprinkle mixture on top of unbaked cake.

For an Apple Sponge Cake: Reduce sugar to 3/4 cup and add 7 to 8 grated apples, 1/4 cup ground almonds, and 1 teaspoon cinnamon.

For a Apple-Filled Cake: Pour 1/2 batter into a 13- by 9-inch pan and bake until lightly colored, about 30 minutes. Sprinkle with 6 peeled, grated, and drained apples, 1/2 cup sugar, 1 tablespoon lemon juice, and 1 teaspoon cinnamon; top with remaining batter; and bake until golden, an additional 55-minutes.

For a Banana-Nut Sponge Cake: Stir 1 1/4 cups mashed bananas and 1 cup chopped walnuts, pecans, or almonds into beaten egg yolks.

For a Carrot Sponge Cake: Add 1 cup grated carrots and, if desired, 1/2 cup raisins or chopped nuts.

For a Chocolate Chip Sponge Cake: Stir in 2 ounces chocolate chips or grated chocolate.

For a Mocha Sponge Cake: Omit lemon and orange and add 2 tablespoons instant coffee powder and 1 tablespoon unsweetened cocoa powder in 1/4 cup boiling water, cool before mixing with egg yolks.

For a Pineapple Sponge Cake: Omit orange juice and zest and add 1/2 cup drained crushed pineapple and 1/2 teaspoon almond extract with lemon juice.

For a Raspberry Sponge Cake: Substitute 2 tablespoons raspberry jelly for orange juice and zest; and add 2 tablespoons finely ground nuts. If desired, spread batter in a 13- by 9-inch baking pan lined with wax paper.

For a Spice Sponge Cake: Reduce matza meal to 3/4 cup; and add 1 cup chopped blanched almonds, 3 tablespoons sweet wine, 2 ounces grated semisweet or bittersweet chocolate, 2 teaspoons cinnamon, and 1 teaspoon ground allspice.