Preheat oven (5 minutes).
Set oven to 400°F. Line a rimmed baking sheet with parchment paper.
Arrange crackers (2 minutes).
Lay saltine crackers in a single layer on the prepared sheet, covering the entire surface.
Make the toffee (5 minutes).
In a saucepan over medium heat, melt butter and brown sugar. Stir constantly until the mixture comes to a boil. Continue boiling for 3 minutes until thickened and bubbly.
Pour and spread (2 minutes).
Carefully pour the hot butter and sugar mixture over the crackers. Spread evenly with a spatula to coat every cracker.
Bake (5 minutes).
Place in the oven for 5 minutes until the toffee is bubbling and slightly golden.
Add chocolate (3 minutes).
Remove from the oven and immediately sprinkle chocolate chips over the hot toffee. Wait 2 minutes for them to melt, then spread into an even layer.
Top & chill (15 minutes).
Sprinkle with candy canes, nuts, or sprinkles. Let cool to room temperature, then refrigerate until set.
Break into pieces & serve.
Once hardened, break it into pieces by hand.