Line a cookie sheet (the kind with sides) with parchment paper or foil.
Cover the lined cookie sheet with saltines-do not overlap.
Bring to a boil the 2 sticks of butter or margarine (I've used better margarine and it works just as well) to a boil.
Add the brown sugar-stir quickly and cook for few minutes-continuing to stir until sugar is melted.
Pour the melted butter/brown sugar combo over the crackers. (Be careful as mixture can REALLY burn you if you're not careful).
Bake at 400°F for 5 minutes.
Remove pan and place on cooling rack.
While pan is still hot-cover with chocolate chips (OKAY, HONESTY CHECK-I don't measure-I grab the bag and dump bout 3/4 of the bag over the hot crackers).
Allow the chips to melt and spread with a spatula.
If adding chopped nuts or sprinkles, add now.
Allow to cool-break apart and enjoy.
I also drizzle white chocolate after the semi-sweet has firmed up OR I've used white chocolate to cover the crackers and sprinkles for the holidays-you could drizzle with regular chocolate or try peanut butter chips and then drizzle with chocolate, even butterscotch chips-there's numerous ways to vary this recipe.