Line 8-inch square pan with Reynolds Wrap® Aluminum Foil, with ends of foil extending over sides; spray foil with cooking spray. Place grahams on bottom of pan, cutting to fit if necessary.

Microwave caramel bits and milk in microwaveable bowl on HIGH 2 min. or until caramel bits are completely melted and mixture is blended, stirring every 30 sec. Pour over grahams; top with next 3 ingredients. Drizzle with chocolate.

Refrigerate at least 1 hour. Use foil handles to remove dessert from pan before cutting into bars to serve.