Step 1: Preheat your oven to 350°F (175°C). Lightly grease a 9x13 inch baking pan or line it with parchment paper, leaving an overhang on the sides for easy removal.
Step 2: For the crust, in a medium bowl, combine the flour, granulated sugar, and salt. Cut in the softened butter with a pastry blender or your fingertips until the mixture resembles coarse crumbs.
Step 3: Press the crust 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.
Step 4: While the crust is baking, prepare the filling. In a large bowl, whisk together the eggs, light corn syrup, packed brown sugar, and vanilla extract until well combined and smooth.
Step 5: Stir in the chopped pecans. Pour the pecan filling evenly over the warm, pre-baked crust.
Step 6: Return the pan to the oven and bake for another 20-25 minutes, or until the filling is set and golden brown. A knife inserted into the center should come out mostly clean.
Step 7: Remove the pan from the oven and place it on a wire rack to cool completely. This is crucial for the bars to set properly. Once cooled, you can chill them in the refrigerator for easier, cleaner slicing.
Step 8: Once thoroughly cooled (and chilled, if desired), lift the bars out of the pan using the parchment paper overhang. Cut into squares and serve.