1 1/2  cups chocolate wafer crumbs 
2  tablespoons sugar 
1/4  cup butter or margarine, melted 
1/4  cup semi-sweet chocolate chips 
1/4  cup heavy whipping cream 
24  ounces cream cheese, softened 
1  cup sugar 
1/3  cup baking cocoa 
3  eggs 
1  teaspoon vanilla 
1 1/2  cups semi-sweet chocolate chips 
1/4  cup heavy whipping cream 
1  teaspoon vanilla 
 
1. In a bowl, combine cookie crumbs and sugar; stir in butter.

2.Press onto the bottom and 1 1/2 in. up the sides of a greased 9 inch springform pan Bake at 180 for 10 minutes. Cool on a wire rack. Reduce heat to 170.

3.In a saucepan over low heat, melt chocolate chips; stir until smooth. Remove from the heat; add cream and mix well; set aside. In a mixing bowl, beat cream cheese and sugar until smooth. Add cocoa and beat well. Add eggs; beat on low just until combined. Stir in vanilla and reserved chocolate mixture just until blended. Pour over crust.

3.Bake for 45-50 minutes or until center is almost set. For topping, melt chocolate chips in a saucepan over low heat, stirring until smooth. Remove from the heat.
Stir in cream and vanilla; mix well. Spread over filling.

4.Refrigerate overnight. Carefully run a knife around the edge of the pan to loosen.
Remove the sides of the pan.