Preheat oven to 325°F Line a 13x9-inch baking pan with foil, with ends of foil extending over sides of pan.
Mix graham crumbs and butter; press firmly onto bottom of pan.
Beat cream cheese, sugar and extract in large bowl with electric mixer on medium speed until well blended. Add sour cream and chocolate; mix well. Add eggs, one at a atime, mixing on low speed after each addition just until blended. Pour over crust.
Bake 40 minutes or until center is almost set. Cool. Refrigerate at least 4 hours or overnight. Lift cheesecake from pan, using foil handles. Top each piece with a dollop of the whipped topping and a candy cane just before serving. Store any leftover cheesecake in refrigerator.