Crust
2 c  Chocolate Wafer Crumbs
1/4 ts Cinnamon
4 tb Unsalted Butter -- melted
Filling
32 oz Cream Cheese -- softened
3/4 c  Sugar
4    Eggs
1/2 c  Sour Cream
1 ts Vanilla
1 c  Semisweet Chocolate Chips
2 tb Grand Marnier
1 ts Grated Orange Peel

Preheat oven to 325.

Mix crumbs, cinnamon, and butter. Press onto the bottom of a 9-inch
springform pan and bake 10 minutes.

Increase oven temperature to 350. Beat cream cheese and sugar at medium
speed until well blended. Add eggs, one at a time, beating well after each
addition. Blend in sour cream and vanilla. Separate batter into 2 equal
parts. Melt chocolate in double boiler and add it to one part. Blend Gran
Marnier and orange peel into remaining part. Pour chocolate batter over
crust and bake 30 minutes.

Reduce oven temperature to 325. Carefully spoon orange batter over
chocolate layer. Continue baking another 40 minutes. Turn off oven and
prop open oven door. Remove cheesecake when oven has cooled. Loosen cake
from rim of pan.