BODY: Combine crumbs and margarine; press onto bottom of 9-inch springform pan. Bake at 350, 10 minutes. BODY: Combine cream cheese and sugar, mixing at medium speed on electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in chocolate, mint wafers, sour cream and vanilla; pour over crust. Bake at 350, 50 minutes. Loosen cake from rim of pan; cool before removing rim of pan. Chill. Garnish with additional mint wafers, if desired.