Combine crumbs, sugar and margarine, press onto bottom of 9-inch spring form pan. Bake at 325 degrees F., 10 minutes. Combine cream cheese, sugar and flour, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in sour cream and vanilla; pour over crust. Bake at 450 degrees F., 10 minutes. Reduce temperature to 250 degrees F.; continue baking for 1 hour. Loosen cake from rim of pan; cool before remobing rim of pan. Chill. Top with pie filling just before serving. VARIATION: Substitute 1 1/2 cups finely chopped nuts and 2 T sugar for graham cracker crumbs and sugar.