Combine crumbs and margarine; press onto the bottom of a 9-inch springform pan. Bake at 350 degrees F., 10 minutes.
Combine cream cheese, sugar and banana, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition.
Stir in walnuts, pour over crust. Bake at 350 degrees F., 40 minutes.
Loosen cake from rim; cool before removing rim of pan.
Melt chocolate pieces and margarine with water over low heat, stirring until smooth. Drizzle over cheesecake. Chill for 24 hours or more. |