Preheat the oven to 350℉ then line a 9 by 13-inch baking pan with parchment paper and spray the sides with nonstick cooking spray.
Whisk together the flour, sugar and salt in a large bowl then cut in the butter using a pastry cutter or a fork until a fine grain starts to form.
Press the mixture into the prepared baking pan in an even layer then bake for 20 minutes.
In the meantime, whisk the eggs and egg yolks, corn syrup and vanilla together in a medium size bowl then stir in the brown sugar.
Stir in the flour and salt then fold in the pecans before letting it rest until the crust is cooked.
When ready, pour the filling onto the crust then bake for 25-30 minutes or until the center is set.
Let the bars cool for at least one hour before slicing and serving.
Storage - Leftovers can be stored in an airtight container at room temperature for up to 5 days. Freezing - The bars can be frozen, cut or uncut, for up to 3 months. I recommend thawing overnight in the fridge before bringing to room temperature.