Cover a cookie sheet with heavy duty aluminum foil. Be sure to use a cookie sheet that has sides, not one that is flat. Preheat oven to 350 degrees.
Line cookie sheet with saltine crackers.
In a saucepan, melt butter and sugar together over medium heat. Allow to come to a boil and set a timer for 5 minutes. Stir constantly.
Pour over the saltine crackers and spread to cover each cracker.
Place in the oven. Cook until it starts to bubble, at least 5 minutes, and then remove from the oven.
Pour chocolate chips over the top and let them melt for about 1 minute. Once softened, spread to each corner. Sprinkle any additional toppings over crackers, if desired. Place in refrigerator until chocolate hardens and the crackers are cooled. Crack or cut into pieces.