Preheat the oven to 350°F. Grease a 9-x-13-inch baking dish and set aside.
To make the shortbread crust: In a large bowl, mix flour, sugar, and salt. Cut in cold butter to create coarse crumbs. Press into the bottom of the prepared dish and bake for 20 minutes.
Meanwhile, prepare the filling: whisk sugar, eggs, corn syrup, melted butter, and vanilla in a large bowl. Stir in pecans. Spread over hot crust as soon as it comes out of the oven.
Bake for 30–35 minutes more, until filling has set.
Cool completely in the pan before cutting into squares and serving.
Video
Notes
Make ahead of time. These bars can be made 24–48 hours in advance. Once cool, cover and store the entire slab in the refrigerator. Use a sharp knife to into squares just before serving.