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.