Preheat your oven to 350°F. Grease a 9x13-inch baking pan or line it with parchment paper for easy removal.
In a medium bowl, combine the flour, softened butter, granulated sugar, and salt. Mix until the mixture resembles coarse crumbs.
Press the mixture evenly into the bottom of the prepared baking pan to form the crust. Bake for 15 minutes or until lightly golden.
While the crust is baking, prepare the filling. In a large bowl, whisk together the corn syrup, brown sugar, eggs, vanilla extract, and cinnamon until well combined. Stir in the chopped pecans.
Once the crust is done baking, remove it from the oven and pour the pecan filling over the hot crust. Spread it evenly.
Return the pan to the oven and bake for an additional 25-30 minutes, or until the filling is set and slightly puffed.
Allow the bars to cool in the pan for at least 1 hour before cutting into squares. For best results, chill in the refrigerator for another hour before serving.