Combine crumbs; sugar, and margarine; press onto bottom and sides of 9" springform pan.Combine softened cream cheese, sugar, cocoa and vanilla, mixing on electric mixer until well blended. Blend in eggs; pour into crust. Bake at 375* for 30 minutes. Combine sour cream, sugar and vanilla; carefully spread over cheesecake. Bake at 425*, 10 minutes. Loosen cake from rim of pan. Cool; remove rim. Chill. From Philadelphia Brand Cream Cheese Cookbook.