Preheat oven to 350F and line a 9×13 baking pan with aluminum foil. Spray the foil with nonstick cooking spray – DO NOT FORGO THIS STEP!
Arrange the saltines in a single layer in the pan and break the saltines in half as needed to cover the entire pan.
Place the butter in a saucepan and melt over medium heat. Once the butter has melted, add the light brown sugar and stir constantly until it has completely dissolved. This should take just a few minutes.
Evenly pour the mixture over the saltines. Use an offset spatula to spread the mixture over the saltines as needed.
Bake the saltine/toffee mixture for 7-8 minutes, or until the toffee is bubbling.
Remove the pan from the oven and place it on a cooling rack. Sprinkle the chocolate chips on top immediately. Give the chocolate chips around 5 minutes to soften and spread it over the mixture with an offset spatula.
Sprinkle with the desired topping(s) — sprinkles, sea salt, chopped nuts, nonpareils, etc. Have fun here!
Leave the pan on the cooling rack for about 30 minutes, then move it to the refrigerator and allow it to cool for about an hour so that the chocolate sets.