Preheat oven to 350f.

Prepare the crust: Grind cookies into fine crumbs using a blender or a food processor fitted with a metal blade. Add butter and blend until smooth. Press crust into bottom of a 9-inch springform pan, and refrigerate while preparing the filling.

Prepare the filling: Beat cream cheese until smooth in a large bowl using an electric mixer. Blend in sugar and sour cream. Add the eggs and vanilla, and mix until smooth.

Using a wooden sppon, stir 1 cup of the chocolate chips. Pour filling into the crust-lined pan, and smooth top with spatula. Sprinkle the remaning cup chocolate chips evenly over the top. Bake 30 to 40 minutes. Turn oven off and leave cheesecake in oven for 1 hour to set. Remove from oven and chill in refrigerator until firm, about 3 or 4 hours.