Heat oven to 325°F Line 13x9-inch pan with foil, with ends of foil extending over sides. Mix graham crumbs, 1/2 cup nuts, and margarine; press onto bottom of pan. Refrigerate until ready to use.
Beat cream cheese and sugar in large bowl, with mixer until blended. Add sour cream, flour and vanilla; mix well. Add eggs, one at a time, mixing on low speed after each just until blended. Pour over crust.
Bake 45 minutes or unti center is almost set. Cool completely. Refrigerate 4 hours. Use foil handles to lift cheesecake from pan. Drizzle with caramel topping; sprinkle with remaining nuts. Let stand until topping is firm.