Crust:

1. Place crumbs in a bowl.

2. Add sugar and butter; stir until well blended.

3. Form crust on bottom and sides of a 9" springform pan

4. Bake crust at 350 F for 10 minutes.

5. Allow crust to cool before filling.

Filling:

6. Place a loaf or cake pan filled with water in the bottom rack of the oven; preheat to 350.

7. Combine chocolate and boiling water in small bowl; stir until chocolate is melted and smooth.

8. In a large bowl, beat cream cheese until smooth.

9. Gradually add, and beat until smooth and creamy, the sugar and vanilla.

10. One at a time, beating until just incorporated, beat in the eggs.

11. Beat in the sour cream and cocoa powder.

12. Add warm chocolate mixture; beat until well blended.

13. Pour filling into crust and smooth.

14. Place springform pan on a baking sheet.

15. Bake 40-45 minutes or until edges have puffed but center is still moist and slightly jiggly.

16. Turn off oven; prop open door with a wood spoon handle and allow to cool for 1 hour.

17. Remove to rack; allow to cool completely.

18. Cover and refrigerate 6-48 hours (longer is better) before serving.