Ricotta Cheesecake in Pine Nut Crust

Microwave butter in a 9-inch glass pie plate on HIGH for 1 to 1 1/2 minutes, or until melted. Stir in vanilla wafer crumbs and pine nuts until well blended. Press firmly against the bottom and sides to form a crust. Microwave on HIGH for 1 1/2 to 2 1/2 minutes, or until set, rotating the dish once halfway through the cooking time. Set aside. In a microwave-safe bowl, combine together ricotta cheese, sour cream, sugar, eggs, flour and grated lemon peel. Microwave on HIGH for 6 to 10 minutes, or until very warm, stirring every two minutes. The mixture will be lumpy at this point, but it will cook into a smooth pie. Pour the filling into the crust, smoothing evenly on top. Place the pie dish on top of a microwave-safe bowl and microwave on MEDIUM for 8 to 14 minutes, or until the center is almost set, rotating once or twice. (When you touch the top with your finger the cheesecake underneath should feel moist but be set, not gooey; the sides will begin to pull away from the crust). Cool for 30 minutes and then chill for 3 hours before serving.