CRUST:

8 oz. chocolate wafers (Nabisco)
3 oz. (3/4 stick) unsalted butter, melted

FILLING:

12 oz. semi-sweet chocolate (melt in microwave 3-4 min. at moderately high temp.)
24 oz. cream cheese, room temperature
1 tsp. vanilla extract
1/8 tsp. salt
1 c. granulated sugar
3 eggs (lg. or extra lg.)
1 c. sour cream

Adjust rack one third up from the bottom of the oven; preheat oven to 375 degrees. Separate the bottom from the sides of a 9"x3" springform pan. Butter the sides only. Replace bottom in pan and set aside.

CRUST: Crumble cookies into food processor and process until fine crumbs. add melted butter and process until thoroughly mixed. Pour 2/3 of mixture into pan. Tilt pan and press a layer of crumbs along the sides leaving a rim of uncrumbed pan 3/4" along the top. Press remaining crumbs evenly around the bottom of the pan.

FILLING: Cream the cheese in the food processor until smooth. Add vanilla, salt, sugar and process briefly. Add chocolate and process until thoroughly mixed, stopping several times to scrape the sides. Add eggs, 1 at a time while processing. Add sour cream. Process until thoroughly mixed, stopping several times to scrape the sides. Pour into prepared pan. Bake for 1 hour. Let stand on rack until completely cool then refrigerate covered with aluminum foil.