HEAT oven to 350°F. Spray 13 x 9-inch baking pan with no-stick cooking spray.
COMBINE graham cracker crumbs and butter in small bowl. Press into bottom of prepared pan. Top evenly with coconut. Pour sweetened condensed milk evenly over coconut layer.
BAKE 25 to 30 minutes or until lightly browned. Loosen from sides of pan while still warm. Melt chocolate chips with peanut butter in small microwave-safe bowl on HIGH for 1 minute. Stir until smooth. Spread evenly over hot coconut layer. Cool 15 minutes on wire rack. Refrigerate 45 minutes or until chocolate is set. Cut into bars or diamonds.
For perfectly cut cookie bars, line entire pan with foil, extending foil over edge of pan. Coat lightly with no-stick cooking spray. After bars have baked and cooled, lift up with edges of foil to remove from pan. Cut into individual bars.