1 lb. ricotta cheese
1 lb. cream cheese
16 oz. sour cream
1/4 lb. butter, melted
2 tsp. vanilla
3 tbsp. flour
3 tbsp. cornstarch
1 1/2 c. sugar
4 eggs

Cream ricotta and cream cheese. Add sugar and beat well. Add eggs, one at a time, continue beating; add vanilla.

Mix in cornstarch, flour, sour cream and melted butter. Grease 10 1/4 inch springform pan. Bake at 350 degrees for 1 hour. Turn off oven and allow cheesecake to remain in the oven for 2 more hours. Cool at room temperature, then cover and refrigerate. Best if refrigerated overnight. Serve chilled.