6 eggs, separated
1 c. sugar
1 tbsp. lemon juice
1 tbsp. orange rind grated
1 c. sifted cake flour
1 1/2 tsp. baking powder
1/4 tsp. salt

CUSTARD FILLING:

1/2 c. sugar
1/4 c. cornstarch
1/8 tbsp. salt
2 c. milk
3 egg yolks, lightly beaten
1/2 c. dark rum
1/2 tsp. vanilla extract
2 tbsp. creme de cocao
1/4 c. Marsala

TOPPING:

1 c. heavy cream, whipped

Preheat oven to 350 degrees. Grease and flour a 9 inch springform pan. Beat egg yolks until they are thick and pale; gradually beat in sugar until it spins a rope when dropped from beaters. Beat in lemon juice and the orange rind. Sift together twice the flour, baking powder and salt and fold into the yolk mixture.

Beat egg whites until stiff and fold into the cake batter; pour into prepared pan and bake 45 minutes. Cool. Combine sugar; cornstarch and salt in pan. Stir in milk, bring to a boil, stirring and cook 1 minute.

Pour a little of hot mixture into egg yolks and mix and return all to pan. Heat 1 to 2 minutes until thickens. Divide filling into 3 bowls. Add 2 tbsp. of rum to first bowl and chill. Add vanilla to second bowl and creme de cacoa to third and chill.

Split sponge cake into 3 layers and sprinkle all layers with remaining rum mixed with Marsala. Place bottom layer in shallow dish. Spread with one of cooled custards. Repeat with other layers and custards.