HEAT oven to 325°F.
MIX wafer crumbs, 1/2 cup nuts and butter; press onto bottom of 13x9-inch 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, 1 at a time, mixing on low speed after each just until blended. Pour over crust.
BAKE 45 min. or until center is almost set. Cool. Refrigerate 4 hours. Drizzle with topping; top with remaining nuts. Let stand until topping is firm.Kraft Kitchens Tips Size-Wise Make a celebration extra special with these indulgent cheesecake bars. Easy Cleanup
Line pan with foil, with ends of foil extending over sides. Use foil handles to lift chilled cheesecake from pan