Adjust the oven rack to the middle position and preheat the oven to 350 degrees F. Line a 9x13-inch baking pan with aluminum foil, leaving an overhang on all sides. Spray the foil lightly with nonstick cooking spray.
In a medium bowl sift together the flour and powdered sugar. Using a pastry cutter, cut in the butter until the mixture resembles fine crumbs. While still in the bowl, knead the dough until smooth, about 10 times. Pat the dough evenly into your prepared baking pan and prick with a fork 25-30 times.
Bake for 15-20 minutes, or until light brown in color. Move to a wire rack.
MAKE PECAN PIE FILLING:
While the shortbread crust is baking prepare the filling. In a medium bowl add the eggs and sugar and beat until combined, about 1-2 minutes.
Add the corn syrup, butter, vanilla, and salt and beat until combined, about 1 minute.
Fold the pecans into the butter and corn syrup mixture.
Pour the filling over the crust and bake until the topping is golden brown and set about 25-35 minutes.
Let cool for at least 2 hours and then cut into 16 squares. Serve.
These bars are very rich, so that's why I suggest cutting them into 16 squares. These smaller squares are perfect for Thanksgiving when folks want to try multiple desserts.