Lemon Swirl Marble Cake

FILLING:
8 egg yolks
1 cup sugar
1/2 cup lemon juice
1/4 cup butter
2 tablespoons lemon rind, grated

CAKE:
2 packages - pound cake mix
1 cup milk
1/2 cup orange juice
1 tablespoon orange rind
8 bunches egg whites
1/2 teaspoon cream of tartar

GLAZE:
2 cups powdered sugar
2 tablespoons light cream
2 tablespoons lemon juice and rind

FILLING: In double boiler with wooden spoon beat yolks. Stir in sugar and rest of ingredients. Cook, stir occasionally over simmering water till thick and smooth. cover and set aside.

CAKE: Heavily grease and flour bundt pan. Put cake mix into large bowl. Add milk, blend till moistened. Add juice, beat 2 minutes. Add rind. In another bowl, beat whites and cram of tartar till stiff peaks are formed. Gently fold whites into batter. (1 cup may be kept for cupcakes.) Pour 1/4 batter into pan. Spoon 1/3 filling over center of batter not touching pan. Repeat, layering twice, end with batter. With knife cut through batter and filling. make a zigzag around pan. Bake for 1 hour, 20 minutes. Press with tip of finger for doneness. Cool in pan for 10 minutes.

GLAZE: Mix all ingredients together and spread over cake.