PREHEAT oven to 350°F. Place 14 of the cookies in food processor container; cover. Process until finely crushed. Mix with butter; press firmly onto bottom of 9-inch square baking pan. Bake 10 min. or until golden brown. Cool 10 min.

PLACE caramels and water in microwaveable bowl. Microwave on HIGH 1 min. or until caramels are completely melted, stirring every 30 sec. Set aside. Coarsely chop remaining 10 cookies. Beat cream cheese and marshmallow creme in large bowl with electric mixer on medium speed until well blended. Add egg; mix well. Stir in chopped cookies; pour over crust. Drop spoonfuls of the caramel mixture over batter; swirl gently with knife for marble effect.

BAKE 20 to 25 min. or until centre is almost set. Cool completely. Refrigerate 4 hours or overnight. Cut into 20 bars. Store in tightly covered container in refrigerator.