Line 13x9-inch pan with foil, with ends extending over sides. Grease foil; set aside. Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted. Stir until chocolate is completely melted.
Add sugar; mix well. Blend in eggs and vanilla. Stir in flour and nuts until well blended; 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.
Use foil handles to lift brownies from pan.
Cut into egg shapes with 3-inch oval cookie cutter. Decorate with decorating gels and candies to resemble Easter eggs.
