Place crackers on bottom of buttered 12 x 7 glass pan. Set this aside. Combine butter and brown sugar in a 4 cup glass measure cup and micro on Roast (Med Hi) for 2 minutes or until butter is melted. Stir in nuts and pour this mixture over the crackers. Micro on Roast for 4 - 5 minutes or until bubbly. Top with Choc chips and continue cooking on Roast for 1 1/2 minutes until chocolate is softened. Spread across the top. Chill 30 min. And cut or break into eating pieces.