SUNNY SPONGE CAKE

Steps:

• Let egg whites and egg yolks stand at room temperature for 30 minutes. Sift together the flour, baking powder and salt; set aside. , In a large bowl, beat egg yolks until slightly thickened. Gradually add 3/4 cup sugar and hot water, beating until thick and pale yellow. Blend in the orange juice, vanilla and orange and lemon zests. Add reserved flour mixture to egg yolk mixture., In another bowl and with clean beaters, beat the egg whites on medium speed until soft peaks form. Gradually beat in sugar, about 1 tablespoon at a time, on high until stiff glossy peaks form and sugar is dissolved. Fold a fourth of egg whites into the batter, then fold in remaining whites., Spoon batter into an ungreased 10-in. tube pan. Bake on the lowest rack at 350° for 25-30 minutes or until cake springs back when lightly touched. Immediately invert pan; cool completely. Run a knife around sides and center tube of pan. Invert cake onto a serving plate. Serve with whipped topping.