Combine 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 blended.
Add melted 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 cheesecake 4 hours.