Preheat your oven to 350°F. Lightly coat an 8x8-inch baking pan with cooking spray. Line the pan with parchment paper, leaving extra paper on the sides for an easy lift later.
To make the crust, beat the room temperature butter with the vanilla, granulated sugar, and salt until creamy. Stir in the flour until a crumbly dough forms.
Press the dough evenly into the prepared pan. Dust your hands or a flat measuring cup with a little extra flour to press down with if needed. Bake for 20 minutes or until the edges start to turn golden.
While the crust bakes, make the filling by whisking together the corn syrup, brown sugar, salt, eggs, flour, and vanilla extract in a bowl until smooth.
Stir in the chopped pecans. Remove the crust from the oven and immediately pour the filling over it, spreading it into an even layer.
Return to the oven and bake for 25 to 30 minutes, or until the filling is set and dark golden around the edges.
Allow the baked bars to cool completely in the pan, then transfer to the refrigerator and chill for at least 1 hour. Once chilled, lift the bars out using the parchment overhang. Cut into 12 bars and serve.