1 sleeve (about 35–40) dry uncrushed saltine crackers1 cup (2 sticks / 226 g) unsalted butter1 cup (200 g) packed light brown sugar1 1/2 cups (255 g) semi-sweet chocolate chips
Preheat your oven to 400°F (200°C). Line a metal sheet pan (roughly 10×15 inches) with foil or parchment, then lightly grease it to help with later removal.
Arrange the dry, uncrushed saltine crackers in a single, tight layer on the prepared sheet pan. The crackers should cover the pan completely with minimal gaps; break a few crackers only if needed to fit the edges.In a medium saucepan over medium heat, combine the butter and brown sugar. Stir continuously as the butter melts and the sugar dissolves. Once it comes to a full bubble, let it cook, stirring, for about 3 minutes until the mixture looks thickened and glossy like a loose caramel.
Carefully pour the hot butter–brown sugar mixture evenly over the saltine crackers, using a heatproof spatula to gently nudge it so all crackers are coated. Work quickly so the toffee doesn’t set in one spot.Place the sheet pan in the preheated oven and bake for 5–7 minutes, or until the toffee layer is bubbling vigorously across the entire surface and darkened slightly in color. Watch closely near the end to avoid burning.
Remove the pan from the oven and immediately sprinkle the chocolate chips in an even layer over the hot toffee-covered crackers. Let them sit for 2–3 minutes so the residual heat melts the chocolate.Using an offset spatula or the back of a spoon, gently spread the softened chocolate into a smooth, even layer over the toffee and crackers, reaching all the way to the corners of the pan.Allow the pan to cool at room temperature until it is no longer hot, then transfer it to the refrigerator and chill for at least 1–2 hours, or until the chocolate is fully set and the toffee is firm.
Once firm, lift the foil or parchment to remove the slab from the pan. Break the sweet into irregular pieces with your hands or cut into neat squares with a sharp knife.Store the pieces in an airtight container at cool room temperature for up to 5 days, or in the refrigerator if your kitchen is warm and the chocolate seems soft.
