Preheat your oven to 350°F (175°C).
Line a baking sheet with parchment paper.
Arrange saltine crackers in a single layer on the baking sheet.
In a saucepan, melt the butter over medium heat.
Stir in the brown sugar and bring to a boil for 3 minutes.
Pour the toffee mixture evenly over the saltine crackers.
Bake in the preheated oven for 5-7 minutes until bubbly.
Remove from the oven and sprinkle chocolate chips on top.
Let the chocolate sit for a few minutes to melt, then spread it evenly.
Optionally, sprinkle chopped nuts over the chocolate before it sets.