Mix ingredients for crust and spread on bottom of a spring form cake pan. Beat cottage cheese and cream cheese until creamy. Blend in sugar and eggs. Add flour and vanilla. Add melted margarine and sour cream. Pour mixture over crust and bake 1 hour and 10 minutes. Bake at 325. turn off oven and let stand in oven for 2 hours. Remove; chill and add topping beforeserving.