### Instructions:
1. **Preheat Oven & Prepare Pan:** Preheat your oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out later. Lightly grease the parchment paper.
2. **Make the Shortbread Crust:** In a medium bowl, whisk together the flour, granulated sugar, and salt. Cut in the softened butter with a pastry blender or your fingertips until the mixture resembles coarse crumbs. Press the mixture evenly into the bottom of the prepared baking pan. Bake for 15-18 minutes, or until lightly golden brown. Remove from oven and set aside.
3. **Prepare the Caramel Filling:** In a heavy-bottomed saucepan over medium heat, melt the butter. Stir in the brown sugar, granulated sugar, and heavy cream. Bring the mixture to a gentle boil, stirring constantly. Reduce heat to low and simmer for 5-7 minutes, stirring occasionally, until the caramel thickens slightly. Remove from heat and stir in the vanilla extract.
4. **Assemble the Bars:** Sprinkle the chopped pecans evenly over the warm shortbread crust. Carefully pour the caramel filling over the pecans, spreading it evenly. Sprinkle the chocolate chips over the warm caramel.
5. **Bake Again:** Return the pan to the oven and bake for another 15-20 minutes, or until the chocolate is melted and glossy, and the edges of the caramel are bubbling.
6. **Cool and Cut:** Remove the pan from the oven and let the bars cool completely on a wire rack before cutting. This is crucial for clean cuts! Once cooled, lift the bars out of the pan using the parchment paper overhang and cut into squares or rectangles.
### Short Tips:
* **Don’t overbake the crust:** You want it just lightly golden, not dark brown.
* **Stir the caramel constantly:** This prevents it from burning or sticking to the bottom of the pan.
* **Let them cool completely!** Seriously, resist the urge to cut into them warm. The caramel needs to set up for perfect squares.
* **For extra flair:** A sprinkle of flaky sea salt on top of the warm chocolate before it sets adds a beautiful contrast in flavor.
* **Storage:** Store leftover bars in an airtight container at room temperature for up to 3-4 days, or in the refrigerator for up to a week.
