For the crust:

1. Preheat the oven to 350°F.
2. In a large bowl, combine the flour, sugar, and salt. Whisk together.
3. Cut the butter into small cubes and work the butter into the flour mixture with your hands. This is called “cutting” the butter in. Keep squishing the butter between your fingers in the flour until no piece is larger than a pea. The resulting mixture will be able to be packed together and will look and feel sandy.
4. In a large 15×10 inch jelly roll pan, pat the crust mixture into the bottom of it. Make sure the crust layer is even and that it is packed tightly. Bake in oven for 20 minutes.

For the filling:

1. While the crust is baking, make your filling.
2. In a large bowl, whisk together corn syrup, both sugars, eggs, vanilla and melted butter.
3. With a spatula, fold in the chopped pecans.
4. When the crust has baked for 20 minutes, take it out of the oven and pour the filling over top of it. It does not matter if the crust is still hot, and it is okay if the crust has cracked a little during its time baking, the filling will hold everything together. Make sure that the filling is evenly distributed over the crust.
5. Place back in the oven and bake for 25-30 more minutes until the filling is still a little wobbly in the center. Allow to cool for an hour before cutting and enjoying.