Combine crumbs, cinnamon and margarine; press onto bottom of a 9-inch springform pan. Bake at 325 degrees F., 10 minutes. 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 sour cream and vanilla. Blend chocolate into 3 cups batter; blend liqueur and peel into remaining batter. Pour chocolate batter over crust. Bate at 350 degrees F., 30 minutes. Reduce oven temperature to

325 degrees F. Spoon remaining batter over chocolate batter continue baking 30 minutes more. Loosen cake from rim of pan; cool before removing rim of pan. Chill.