Line large jelly roll pan with foil, spray with pan and arrange saltines salt side down in single layer. Melt butter and b sugar together and boil a few minutes until caramel color. Pour over crackers. Bake 425 degrees 3 to 5 minutes until just bubbly. Remove from oven and pour choc chips over. When melt a bit, spread to cover crackers. Freeze 15 to 20 minutes. Break into pieces. Store in refrigerator or freezer