Line cookie sheet with foil and spray with non-stick cooking spray. Line cookie sheet with saltine crackers in single layer.
In a saucepan combine the sugar and the butter. Bring to a boil and boil for 3 minutes. Immediately pour over saltines and spread to cover crackers completely.
Bake at 400 degrees for 5 to 6 minutes, or until mixture is bubbly. Remove from oven and sprinkle chocolate chips over the top. Let sit for 5 minutes. Spread melted chocolate and top with chopped nuts, if desired. Cool completely and break into pieces.
Note: You can also use Peanut butter chips plus the chocolate chips...or pick one to use.