Chocolate Chunk Cheesecake

2 cups finely crushed cream-filled Oreos  (about 20 cookies)
2 T butter, melted
4 (8oz.) packages cream cheese, softened
1 ½ cups sugar
4 eggs
2 tsp. vanilla
1 ¾ (11.5- oz package) semisweet chocolate chunks, divided
1 ½ cups coarsely crushed Oreos  (about 14 cookies)
1/3 cup whipping cream

Stir together 2 cups cookie crumbs and butter; press mixture into bottom and ½ inch up sides of a 9-inch springform 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, 1 cup chocolate chunks, and 1 ½ cups coarsely crushed cookies.  Pour into prepared crust.

Bake at 325 degrees for 55 minutes or until center is almost set.  Turn off oven; let cheesecake stand in oven, with oven door partially open, 20 minutes.

Remove cheesecake from oven, and cool in pan on a wire rack 30 minutes.  Cover cheesecake, and chill 8 hours.  Release sides of pan.

Microwave remaining ¾ cup chocolate chunks and whipping cream in a glass bowl at HIGH 1 minute; stir until chocolate melts.  Chill 30 minutes.  Pour over cheesecake.