Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Arrange the saltine crackers in a single layer on the prepared baking sheet.
In a saucepan over medium heat, melt the butter and brown sugar together. Bring to a gentle boil and cook for 3–4 minutes, stirring constantly, until thickened.
Pour the toffee mixture evenly over the crackers and smooth out with a spatula.
Bake for 5 minutes to set the toffee.
Remove from the oven and immediately sprinkle chocolate chips on top. Let sit for 2 minutes, then spread the melted chocolate evenly.
Sprinkle broken pretzels and chopped peanuts over the chocolate layer.
Refrigerate for 1 hour or until fully set. Break into pieces and enjoy!