MIX crumbs and margarine; press onto bottom and up side of 9-inch pie plate to form crust. Beat cream cheese, sugar and peanut butter in large bowl with mixer until blended. Gently stir in Cool Whip until blended.
SPOON into crust; drizzle with fudge topping. Swirl gently with knife.
REFRIGERATE 4 hours or until firm. Refrigerate leftovers.
serving size = 1 slice (87 g)