Preheat oven to 425. Line a large or 2 small jelly roll trays with foil and spray with non-stick spray. Arrange the saltines on the foil in a single layer.
In a med saucepan, melt the butter and the sugar and boil for 5 minutes. Pour over the crackers as evenly as possible.
Put in the oven 2-5 min or just until bubbly, watching carefully. Remove from the oven and sprinkle the chips over. When they start to melt a bit, spread with an off-centered spatula and sprinlke with the nuts, if desired.
Transfer to freezer for 15-20 min. Cut or break up as you desire. Store in an air-tight container.