Process 30 cookies in food processor until finely ground. Add butter and mix well. Press into the bottom of a 13x9-inch pan.
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, beating after each just until blended; pour half over crust. Stir melted chocolate into remaining batter; pour over batter in pan. Chop remaining cookies; sprinkle over batter.
Bake 45 min. or until center is almost set. Cool completely. Refrigerate 4 hours.