HEAT oven to 300°F.
MIX cookie crumbs and butter; press onto bottom of 9-inch springform pan.
BEAT cream cheese, sweetened condensed milk and vanilla in large bowl with mixer until well blended. Add chocolate; mix well. Add eggs, 1 at a time, mixing on low speed after each just until blended. Pour over crust.
BAKE 1 hour 5 min. to 1 hour 10 min. or until center is almost set. Run knife around rim of pan to loosen cake; cool before removing rim. Refrigerate 4 hours.