Remove the pie crusts from the refrigerator and let them sit at room temperature for 15 minutes. Roll out one pie crust into a rectangle large enough to cover the bottom and slightly up the sides of your prepared baking pan, aiming for a thickness of about 1/8 to 1/4 inch. Refrigerate the shaped crust for 30 minutes to help it maintain its shape during baking.

Prick the bottom of the chilled crust all over with a fork to prevent bubbling. Line the crust with foil and fill it with pie weights. Bake in a preheated oven at 375°F (190°C) for 15 minutes. I find that using pie weights really helps the crust stay flat.

Whisk together 1 egg and the water in a small bowl to make an egg wash. Remove the crust from the oven, take out the foil and pie weights, then lightly brush the bottom of the crust with the egg wash. Return the crust to the oven (without weights) and bake for another 5 minutes until lightly golden. Set aside to cool while you prepare the filling. Leave the oven on.

In a medium mixing bowl, stir together the brown sugar, granulated sugar, flour, and salt until evenly combined. Set the dry mixture aside for the next step.

In a large mixing bowl, lightly beat the remaining 3 eggs. Stir in the melted and cooled butter, bourbon (or half and half), and vanilla extract. Gently mix in the dry sugar mixture from Step 4, then fold in the lightly toasted chopped pecans and chocolate chips. Be careful not to overmix the batter. Spread the filling evenly over the cooled pie crust from Step 3.

Bake the assembled bars in the preheated oven for 18 to 22 minutes, or until the filling is set and the bubbling has subsided. Allow the bars to cool completely before cutting. I like to let them rest until fully cool so the bars slice neatly and hold their shape.