MIX cookie crumbs and butter; press onto bottom of foil-lined 13x9-inch pan. Bake 10 min.
2
BEAT cream cheese, sugar and vanilla in large bowl with mixer until well blended. Add sour cream; mix well. Add eggs, 1 at a time, mixing after each just until blended.
3
RESERVE 1 cup batter. Stir chocolate into remaining batter; pour over crust. Top with spoonfuls of reserved plain batter.
4
SWIRL batters with knife. Bake 40 min. or until center is almost set. Cool. Refrigerate 4 hours.