Prepare the Baking Dish:

• Preheat the oven to 350°F (175°C).

• Line a 9×13-inch baking dish with parchment paper, leaving an overhang on two sides for easy removal. Lightly spray with nonstick cooking spray to secure the paper.

• Tip: Ensure the parchment covers the sides to prevent caramel from sticking, and press it firmly into the corners.

Layer the Pretzels:

• Crush 2 cups pretzels into small pieces (about ½-inch) using a rolling pin or food processor, keeping some texture for crunch.

• Spread the crushed pretzels evenly over the bottom of the prepared baking dish, covering the entire surface.

• Tip: Avoid crushing into fine crumbs to maintain crunch, and press lightly to create an even layer.

Make the Caramel Sauce:

• In a medium saucepan, melt 1 cup unsalted butter over medium heat, about 1–2 minutes.

• Stir in 1 cup packed brown sugar and cook, stirring constantly with a whisk or wooden spoon, until the mixture is smooth and starts to bubble, about 2–3 minutes.

• Remove from heat and stir in ½ tsp vanilla extract until fully combined.

• Tip: Stir continuously to prevent burning, and cook until the mixture thickens slightly but remains pourable.

Pour the Caramel:

• Pour the hot caramel sauce evenly over the pretzel layer, using a spatula to spread it to the edges and cover all pretzels.

• Tip: Work quickly as the caramel thickens as it cools, and tilt the dish if needed to ensure even coverage.

Bake:

• Bake in the preheated oven for 10–12 minutes, or until the caramel is bubbly and golden brown across the surface.

• Check for doneness: the caramel should look set but not overly dark.

• Tip: Rotate the dish halfway through if your oven has hot spots, and watch closely to avoid overbrowning.

Add the Chocolate Layer:

• Remove the dish from the oven and immediately sprinkle 1½ cups semisweet chocolate chips evenly over the hot caramel layer.

• Let the chocolate chips sit for 2–3 minutes to soften, then use a spatula or the back of a spoon to spread them into a smooth, even layer.

• Tip: Spread gently to avoid disturbing the caramel, and ensure the chocolate reaches the edges for a uniform topping.

Add Optional Sea Salt:

• If using, sprinkle a pinch of sea salt lightly over the melted chocolate layer for a sweet-salty contrast.

• Tip: Use a light hand to avoid oversalting, and opt for flaky sea salt for a delicate crunch.

Cool and Set:

• Allow the bars to cool completely at room temperature (about 40 minutes) or in the refrigerator (20–30 minutes) until the chocolate is fully set and firm.

• Tip: Refrigerate for faster setting, but let the bars sit at room temperature for 5 minutes before cutting to avoid cracking the chocolate.

Cut and Serve:

• Use the parchment paper overhang to lift the bars out of the baking dish and transfer to a cutting board.

• Cut into 12 bars (or smaller pieces for bite-sized treats) using a sharp knife, wiping the blade between cuts for clean edges.

• Serve at room temperature, optionally with coffee, milk, or hot cocoa for a cozy treat.

• Tip: Run the knife under hot water for smoother cuts, and arrange bars on a platter for sharing.