How to Make It
Lightly coat an 8-inch square baking dish with cooking spray. Place condensed milk and chocolate chips in a medium microwave-safe bowl. Microwave on high, stirring every 30 seconds, until melted and smooth, about 1½ minutes. Stir in 2 cups of the crushed cookies. Pour mixture into prepared baking dish and smooth top. Sprinkle with remaining cookies. Chill until firm, 6 hours; cut into 2-inch squares.