Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving an overhang on the long sides to form a sling. Lightly grease the parchment and any exposed sides of the pan with butter or nonstick spray.
nonstick spray or butter, parchment paper
In a medium mixing bowl, whisk together the flour, granulated sugar, and fine sea salt for the crust.
2 cups all-purpose flour, 1/2 cup granulated sugar, 1/2 teaspoon fine sea salt
Add the cold, cubed unsalted butter and vanilla extract to the dry ingredients. Use a pastry cutter, two knives, or your fingertips to work the butter into the mixture until it resembles coarse crumbs with a few pea-sized bits of butter remaining.
1 cup unsalted butter, 1 teaspoon pure vanilla extract
Pour the crumb mixture into the prepared pan and press it firmly and evenly into the bottom using your fingers or the bottom of a measuring cup. Bake the crust for 16–18 minutes, or until the edges are just turning light golden. Do not overbake.
While the crust bakes, prepare the pecan filling. In a large bowl, whisk the eggs until well combined and slightly frothy.
3 large eggs
Add the light corn syrup, packed light brown sugar, melted butter, vanilla extract, and fine sea salt (plus bourbon or maple syrup, if using) to the eggs. Whisk until the mixture is smooth and no streaks of egg or sugar remain.
1 cup light corn syrup, 1 cup light brown sugar, 3 tablespoons unsalted butter, 1 1/2 teaspoons pure vanilla extract, 1/2 teaspoon fine sea salt, 1 tablespoon bourbon, 2 tablespoons pure maple syrup
Stir in the chopped pecans and, if desired, the chocolate chips until everything is evenly coated with the filling mixture.
2 1/2 cups pecans, 1/2 cup semi-sweet chocolate chips
When the crust is done, remove it from the oven but leave the oven on. Give the pecan mixture a quick stir, then pour it evenly over the hot crust. Use a spatula to gently nudge pecans into any bare spots so the surface is evenly covered.
Return the pan to the 350°F (175°C) oven and bake for 25–30 minutes, or until the top is set, puffed in spots, and the center jiggles just slightly (not like loose liquid) when you gently shake the pan. If the edges brown too quickly, tent loosely with foil during the last 5–10 minutes.
Transfer the pan to a cooling rack and let the bars cool completely in the pan, 2–3 hours. For extra clean cuts, chill the cooled pan in the refrigerator for about 1 hour before slicing.
Use the parchment sling to lift the entire slab of pecan bars out of the pan and onto a cutting board. With a sharp knife, cut into about 24 bars or smaller bite-size squares for a dessert tray, wiping the knife clean between cuts for neat edges.