Olive Garden's Peaches 'n Cream Cheesecake

Ingredients:
=== SPONGE CAKE BASE ===
1 egg
1/3 cup sugar
1/4 teaspoon vanilla
1/4 cup all-purpose flour
1/4 teaspoon baking powder
1 pinch salt
2 tablespoons water
=== FILLING ===
2 pounds cream cheese -- softened
1 cup sugar
4 eggs
1 teaspoon all-purpose flour
1 teaspoon vanilla
1 cup sour cream
1/4 cup peach liqueur or peach schnapps or
reserved peach juice from the canned
or fresh peaches
2 cups canned or firm ripe fresh peach slices -- drained well
=== TOPPING ===
1 pint whipping cream or equivalent
Cooking Directions:
For the Base: Preheat oven to 375 degrees. Lightly grease base of 10-inch springform pan.
Beat whole egg in 1 1/2-quart bowl with mixer on high speed, 4 minutes, to a thick yellow foam. Mix in sugar on low speed until smooth. Add flour, water, vanilla, baking powder and salt. Mix on low speed until fully blended. Pour into springform pan, roll around until level. Bake 16 to
18 minutes on lowest oven rack. Cool to room temperature. For the Filling: Preheat oven to 325 degrees. Mix cream cheese, sugar, eggs and flour with electric mixer on high until smooth. Add vanilla, sour cream and peach flavoring and mix on medium until a smooth thick consistency is obtained. Fold in peach slices carefully -- distribute evenly. Pour cheesecake filling onto cooled sponge cake base. Bake 70 minutes on lower oven rack, turn off oven, open oven door to broil position and let cake remain 40 minutes. Cool to refrigerated temperature.
Top with fresh whipped cream or equivalent and serve. Store up to 2 days in the refrigerator.