Preheat oven to 500 degrees. Combine gingersnaps, walnuts, sugar and butter in a medium bowl. Press into the bottom and 1 inch up the side of a 10-inch nonstick springform pan. Set aside. * Beat cream cheese, sugar and flour with an electric mixer until smooth. Add 5 eggs, 1 at a time, then vanilla, beating on low speed. Transfer 2 1/2 Cups to a separate bowl; set aside. * Beat 1 egg, pie spice and pumpkin into remaining filling until smooth. Pour half of pumpkin filling into crust, then half of the plain; repeat. Swirl gently with a spoon. * Bake at 500 degrees for 10 minutes; reduce temperatures to 200 degrees and bake 30 minutes. Tent with aluminum foil and continue baking for 1 hour or until center appears nearly set when shaken. Run a knife around top of cake to loosen from pan. Cool on rack for 30 minutes, then chill in refrigerator at least 6 hours. Makes 12 servings.