Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, letting some hang over the sides for easy removal, or grease it well to prevent sticking.

In a large bowl, combine the melted unsalted butter, all-purpose flour, white sugar, and salt. Mix until a cohesive dough forms. Press this dough evenly into the bottom of the prepared pan, making sure to reach the corners. I find pressing with the bottom of a measuring cup helps achieve an even layer.

Transfer the pan to the preheated oven and bake the crust for 15-18 minutes, or until it appears lightly golden. Remove from the oven and set aside to cool slightly while preparing the filling.

In another large bowl, whisk together the chopped pecans, packed light brown sugar, light corn syrup, eggs, and vanilla extract until well combined. Make sure the mixture is smooth and the eggs are fully incorporated.

Pour the pecan mixture from Step 4 over the cooled, pre-baked crust (from Step 3), spreading it evenly to the edges. Bake in the oven for 30-35 minutes, until the filling is set and golden. Sometimes I loosely cover the pan with foil halfway through baking if the topping browns too fast.

Let the bars cool completely in the pan. This will help them set and make slicing much easier. Once fully cooled, lift them out using the parchment paper, if used, and cut into squares to serve.