STIR together 2 cups cookie crumbs and butter; press mixture into bottom and 1/2 inch up sides of a 9-inch spring-form pan.
BEAT softened cream cheese and sugar at medium speed with an electric mixer until blended. Add eggs, 1 at a time, beating just until blended after each addition. Stir in vanilla extract, 1 cup chocolate chunks, and 1 1/2 cups coarsely crushed cookies. Pour into prepared crust.
BAKE at 325 for 55 minutes or until center is almost set. Turn off oven; let cheesecake stand in oven, with oven door partially open, for 20 minutes.
REMOVE cheesecake from oven, and cool in pan on a wire rack for 30 minutes. Cover cheesecake, and chill 8 hours . Release sides of pan.
MICROWAVE remaining 3/4 cup chocolate chunks and whipping cream in a glass bowl at HIGH 1 minute; stir until chocolate melts. Chill 30 minutes. Pour over cheesecake.Return to fridge until time to serve.