Preheat the oven to 400°F.
Line a cookie sheet or a jelly roll pan with parchment paper. The baking sheet needs to have at least a ½ inch edge.
Lay the saltine crackers in a single layer on the cookie sheet. Do not overlap.
In a small pot, combine the sugar and butter. Bring the mixture to a boil.
Once boiling, continue to cook for 3 minutes until the mixture reaches a deep caramel color. Don't leave the stovetop while it's boiling! Stir the mixture constantly.
After 3 minutes, immediately pour the caramel mixture over the saltines, spreading it to cover the crackers completely.
Bake in the oven for 5 to 6 minutes until bubbly and the crackers look like they are floating.
Carefully remove from the oven and (using a knife or off-set spatula), straighten any crackers that have shifted. Don't touch the crackers with your fingers, you'll get burned!
Sprinkle the chocolate chips over the top and let them sit for a few minutes to melt. If the pan isn't hot enough, you can return it to the oven for a few minutes to melt the chocolate chips.
If you're also using white chocolate chips for decorating, spread those around the top as well.
Spread the melted chocolate evenly. Swirl the white chocolate. Top with chopped nuts, or holiday sprinkles.
Allow to cool completely. To speed up the process, place the pan in the fridge for a few minutes to set the chocolate.
Once set, break into pieces and enjoy!