HEAT oven to 350°F.
LINE 13x9-inch pan with foil, with ends of foil extending over sides; spray with cooking spray. Microwave 4 chocolate squares and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted; stir until chocolate is completely melted. Stir in granulated sugar. Blend in eggs and vanilla. Add flour; mix well. Spread into prepared pan.
BAKE 30 to 35 min. or until toothpick inserted in center comes out with fudgy crumbs. (Do not overbake.) Cool completely in pan. Meanwhile, use decorating gel to decorate cookies to resemble gravestones.
MICROWAVE remaining chocolate squares and COOL WHIP in microwaveable bowl on HIGH 1-1/2 to 2 min. or until chocolate is completely melted; stir until well blended. Add powdered sugar; mix well.
USE foil handles to lift dessert from pan; spread with frosting. Stand cookies in brownies; add small amount of coconut at base of each for grass.
A serving of this sweet treat goes a long way on chocolate flavor!
How to Tint Coconut
Place 1/2 cup coconut in resealable plastic bag. Add 2 drops green food coloring. Seal bag; shake to evenly tint coconut.
Prepare as directed, decorating brownies with 12 each JET-PUFFED BOOMALLOWS and NUTTER BUTTER Cookies.