Preheat oven to 400°F (200°C) and line a 10×15-inch jelly roll pan with foil or parchment, leaving some overhang.

Arrange saltine crackers in a single, tight layer, breaking a few to fill gaps.

Melt butter in a saucepan over medium heat, then stir in brown sugar.

Once bubbling, boil for exactly 3 minutes while stirring constantly until thickened slightly.

Pour the hot toffee evenly over the crackers and spread to coat.

Bake for 5 minutes until bubbly and golden. Remove from oven and sprinkle chocolate chips on top.

Let sit 2–3 minutes to soften, then spread evenly. While warm, add toppings like pecans, crushed candy canes, or sea salt.

Chill for at least 2 hours until firm, then lift out using the parchment and break into pieces or cut neatly.