CRUST:

1 pack graham crackers
3/4 c. sugar
1 stick butter

FILLING:

15 oz. ricotta cheese
1 lb. cream cheese
1 pt. sour cream
1 stick butter
1 1/2 c. sugar
3 tbsp. flour
3 eggs
1 tsp. vanilla
3 tbsp. cornstarch
Juice of 1 lemon

CRUST: Mix graham cracker crumbs with sugar and melted butter and press into 9" springform pan.

FILLING: Cream shortening, add cheeses, beat well. Beat in sugar thoroughly. Beat in eggs, add dry ingredients, beat well. Add juice and vanilla. Pour filling over crust, put in COLD oven, turn to 350 degrees. Bake 1 hour. Shut oven off, leave in until cold or 1 hour.