Line a jelly roll pan with foil and grease lightly. Completely line the pan with the crackers. Boil butter and brown sugar for three minutes, stirring constantly. Pour mixture over crackers. Bake at 375 degrees for five minutes. Remove from oven. Sprinkle chips over pan. Let chips soften so they can be evenly spread. Spread them all over the toffee mixture. Sprinkle nuts over top. Refrigerate for one hour and then break apart into bite-sized pieces. Store in the refrigerator! YUMMY!