1 lb. ricotta cheese, room temperature
2 pkgs. cream cheese (8 oz. each)
1 1/2 c. sugar
4 eggs
1/2 tsp. vanilla
1/2 tsp. lemon juice
3 tbsp. cornstarch
3 tbsp. flour
1/4 c. melted butter
1 pt. sour cream

Blend the ricotta and cream cheese together. Blend in the sugar. Beat in eggs, one at a time. Add the vanilla, lemon juice, cornstarch, flour and butter. Fold in the sour cream and blend well. Pour into a 10 inch buttered spring form pan. Place in a cold oven and turn heat on to 325 degrees. Bake for 1 hour. Do not open door. Turn off oven and leave until cool, at least 2 hours.