For the crust:
1-1/2 cups very finely crushed chocolate cookie crumbs (I use about 30 Nabisco Famous Chocolate Wafers)
3 Tbs. granulated sugar
1/8 tsp. ground cinnamon (optional)
1/4 cup unsalted butter, meltedFor the filling:1/2 cup sour cream
2 tsp. pure vanilla extract