Mix ricotta cheese, sour cream, and cream cheese together thoroughly with electric beater. Add and beat flavorings, flour, cornstarch, melted butter and sugar. Separate the eggs and beat the whites until stiff. Then fold in the whites by hand. Pour mixture into oiled springform pan with crust on bottom. Bake at 350 degrees for 1 1/4 to 1 1/2 hours.

Then shut oven off and let cheesecake sit in oven for 2 hours. Do not open oven door entire time cheesecake is in oven otherwise it will fall. Remove and top with fruit topping. Refrigerate. 12 or more servings.