For the Crust:
In medium bowl, stir all ingredients until well mixed. Press mixture firmly against bottom of 9-inch baking dish.
For the Filling:
In a mixing bowl, beat cream cheese, ricotta and sugar until smooth. Add the eggs, one at a time, mixing well after each addition. Add butter, cornstarch, flour and vanilla; beat until smooth. Fold in sour cream. Pour on top of your graham cracker crust. Bake, uncovered, at 325 degrees for 1 hour. Do NOT open oven door. Turn oven off. Let cheesecake stand in closed oven for 2 hours. Cool completely on a wire rack. Chill several hours or overnight. Top each square with topping of choice, if desired (Ethan actually prefers his without any toppings, weirdo).