Junior's Famous Cheesecake

This is the original recipe. This is VERY fattening, but if you want the "best" cheescake, this is it! Let the cream cheese warm to room temperature before making the filling. This lets you beat more air into the cheese mixture, making a lighter, higher, yet still creamy cheesecake. This cheesecake is particularly unusual because it has a spongecake layer at the bottom.

THIN SPONGECAKE LAYER:
1/2 cup sifted cake flour
1 tsp. baking powder
pinch salt
3 extra-large eggs, separated
1/2 cup plus 2 tbsp. sugar
1 tsp. pure vanilla extract
3 drops pure lemon extract
3 tbsp. unsalted butter, melted
1/4 tsp. cream of tartar

JUNIOR'S CHEESE FILLING:
4 (8-ounce) packages regular cream cheese, at room temperature
1 2/3 cups sugar
1/4 cup cornstarch
1 tbsp. pure vanilla extract
2 extra-large eggs
3/4 cup heavy whipping cream
water

TO MAKE SPONGECAKE:
Preheat oven to 350 and generously butter a 9-inch springform pan. Sift the cake flour, baking powder and salt together in a medium bowl; set aside.
Beat the egg yolks together in a large bowl with an electic mixer on high speed 3 minutes. Then, with the mixer still running, gradually add 1/3 cup sugar and continue beating about 5 minutes or until thick light-yellow ribbons form in the bowl. Beat the vanilla and lemon extracts into this batter.
Sift the flour mixture over the batter and stir it in by hand until no more white flecks appear. Then blend in the butter.
In a clean bowl, using clean dry beaters, beat the egg whites and cream of tartar
together on high speed of elecric mixer until frothy. Gradually add the remaining 2 tbsp. sugar and continue beating until until stiff peaks form (the whites should stand up, but not be dry). Stir about 1/3 cup of the beaten whites into the batter, then gently fold in the remaining whites (don't worry if a few white specks remain).
Gently spoon the batter into the pan. Bake the cake about 15 minutes or just until the center of the cake springs back when lightly touched (watch carefully; it will not be completely cooked as the cake layer will be cooked more once the filling is added). Let the cake cool in the pan on a wore rack while you continue making the cheesecake.

TO MAKE FILLING:
Meanwhile, place 1 package cream cheese, 1/3 cup sugar and the cornstarch in a large bowl. Beat with an electric mixer 3 minutes on low speed until creamy. Then beat in the remaining 3 packages cream cheese.
Increase the mixer to high and beat in the remaining 1 1/3 cups sugar, then beat in the vanilla. Blend in the eggs, one at a time, beating the batter well after adding each one. Blend in the heavy cream. At this point, mix the filling only until completely blended. Be careful not to overmix the batter.
Gently spoon the cheese filling on top of the baked spongecake layer. Place the springform pan in a shallow pan that is large enough to hold it. Place in the middle of the oven. Fill the shallow pan with enough hot water to come about 1 inch up the side of the springform pan. Bake the cheesecake about 1 hour or until the center barely jiggles when you shake the pan.
Cool on a wire rack 1 hour. Then cover the cake with plastic wrap and refrigerate at least 4 hours or overnight so that it is completely cold. Remove the side of the springform pan. Cut cake into slices and serve. Wrap any leftover in plastic wrap and refrogerate. Makes 8 servings.