Preheat & Prep: Preheat your oven to 350°F (175°C). Lightly grease a 9x13-inch glass casserole dish with a bit of butter, making sure to coat the corners so the bars release easily.

Crush Pretzels: Place the pretzels in a large zip-top bag and crush them with a rolling pin or the bottom of a heavy pan until you have mostly small pieces with a few larger bits for texture. You are aiming for coarse crumbs, not a fine powder.

Mix Crust: In a medium bowl, combine the crushed pretzels and melted butter. Stir until all of the pretzel crumbs are evenly coated and look slightly glossy.

Press Crust: Transfer the buttered pretzel mixture to the prepared glass casserole dish. Press it firmly and evenly into the bottom of the dish using your hands or the flat bottom of a measuring cup.

First Bake: Bake the pretzel crust in the preheated oven for 8–10 minutes, just until it is lightly fragrant and starting to set. Remove the dish from the oven and set it on a heatproof surface. Leave the oven on.

Add Caramel: While the crust is still hot, pour the room-temperature caramel sauce evenly over the surface. Use a spatula or the back of a spoon to gently nudge the caramel into the corners, trying your best not to disturb the crust.

Second Bake: Return the dish to the oven and bake for another 10–12 minutes, until the caramel is bubbling gently around the edges and looks slightly thicker.

Add Chocolate: Carefully remove the pan from the oven and immediately sprinkle the chocolate chips evenly over the hot caramel layer. Let them sit undisturbed for 3–5 minutes.

Spread Chocolate: Once the chocolate chips look glossy and soft from the residual heat, use a small offset spatula or the back of a spoon to gently spread and swirl the melted chocolate over the caramel.

Chill: Allow the bars to cool at room temperature until the glass dish is no longer hot. Transfer the dish to the refrigerator and chill for at least 1–2 hours, or until fully set.

Slice & Serve: When ready to serve, remove the dish from the refrigerator and let it sit at room temperature for about 10–15 minutes to soften slightly. Run a thin knife around the edges, then cut the slab into 16 squares.