Notes from the Test Kitchen:
The different shades of decadent chocolate make this cheesecake a picture perfect dessert. I would normally suggest serving this to impress important guests, but really I recommending serving this at EVERY opportunity!
Heat oven to 300°F. To make crust, stir together vanilla wafer crumbs, powdered sugar, unsweetened cocoa and melted butter or margarine in medium bowl. Press firmly onto bottom of 9-inch springform pan and set aside.
Place chocolate chips in microwave-safe bowl and Microwave at MEDIUM (50%) 1-1/2 minutes; stir. If necessary, microwave at MEDIUM an additional 15 seconds at a time, stirring after each heating, just until chips are melted when stirred.
Beat cream cheese in large bowl until fluffy. Gradually beat in sweetened condensed milk until smooth. Add melted chips, eggs and vanilla; mix well. Pour into prepared crust.
Bake 1 hour and 5 minutes or until center is set. Remove from oven to wire rack. With knife, loosen cake from side of pan. Cool completely; remove side of pan. Refrigerate several hours before serving. Garnish as desired. Cover; refrigerate leftover cheesecake.