Heat oven to 350°F. In medium bowl, combine graham cracker crumbs, walnuts and butter; mix well. Press in bottom and 1 1/2 inches up sides of ungreased 10-inch springform pan. Bake at 350°F. for 8 to 10 minutes or until set.
Meanwhile, beat cream cheese in large bowl at medium speed until smooth and creamy. Gradually beat in 1 cup syrup, brown sugar and flour until well blended. At low speed, add eggs 1 at a time, beating just until combined. Add melted chocolate and maple flavor; beat until smooth.
Remove crust from oven. Reduce oven temperature to 325°F. Pour cream cheese mixture into crust. Return to oven. Bake at 325°F. for 55 to 65 minutes or until set. Cool on wire rack 30 minutes.
Run knife around edges of cheesecake to loosen. Cool 2 hours or until completely cooled. Refrigerate at least 8 hours before serving.
Just before serving, in small bowl, beat cream and 1 tablespoon syrup until stiff peaks form. Carefully remove sides of springform pan. Spoon or pipe topping around edge of cheesecake. Cut into wedges.