HEAT oven to 350°F.
LINE 13x9-inch pan with foil, with ends of foil extending over sides. Spray with cooking spray. Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted; stir until chocolate is completely melted. Stir in sugar, flour, nuts, eggs and vanilla.
POUR into prepared pan.
BAKE 30 to 35 min. or until toothpick inserted in centre comes out with fudgy crumbs. Cool completely. Use foil handles to lift dessert from pan. Cut into 24 brownies, using 2-inch oval-shaped cookie cutter. Reserve trimmings for snacking or another use.
DECORATE with remaining ingredients to resemble Easter eggs.
serving size = 1 brownie (30 g)