Mix cookie crumbs with butter; press into 8-by-8-inch baking pan. Combine gelatin with 1 tbsp. water; let sit 5 minutes. Meanwhile, beat cream cheese, condensed milk and peanut butter. Microwave gelatin 20 to 30 seconds to melt; beat into cream cheese mixture. Stir in chocolate chips. Fill pan and freeze 20 minutes. Cut into bite-size squares.