1Heat oven to 400°F. Line cookie sheet with sides with foil. Place crackers in single layer on cookie sheet.
2In 1-quart saucepan, heat butter and sugar over medium heat, stirring frequently, until melted and smooth. Pour over crackers; spread evenly to cover all crackers.
3Bake 3 to 5 minutes or until bubbly and golden. Remove from oven. Immediately sprinkle chocolate chips evenly over crackers.
4Return to oven; bake 1 to 2 minutes longer. Spread chocolate over all crackers. Sprinkle with desired toppings. Refrigerate until completely cooled. Break into pieces to serve. Store in refrigerator.