Put a piece of parchment paper in a 15x10 rimmed pan. Put a layer (40) soda crackers on the paper.
Boil the butter and sugar together for 2 minutes. Pour over the crackers. Bake 10 minutes at 350 degrees. Take out of the oven, sprinkle with the chocolate chips on the top. Spread as they melt. Sprinkle chopped nuts over the chocolate. Chill in refrigerator. Break into pieces, store in covered container in the refrigerator.