Preheat the oven to 350°F. Line a 9 × 13-inch baking pan with parchment paper, leaving enough excess paper along the sides to serve as handles when removing the finished bars.
Combine the all-purpose flour and granulated sugar in a medium mixing bowl. Add the softened unsalted butter and work it into the dry ingredients with a fork or your fingertips until the mixture develops a coarse, breadcrumb-like consistency.
Transfer the crust mixture to the lined baking pan. Press it firmly into an even layer, extending it carefully into the corners and slightly upward along the edges of the pan.
Bake the crust for 15 minutes, or until it is set and lightly golden without becoming deeply browned.
While the crust is baking, whisk the eggs, light corn syrup, packed brown sugar, melted and slightly cooled butter, and vanilla extract together in a large bowl until the mixture is smooth and thoroughly blended.
If using bourbon, stir it into the filling at this stage according to taste. Approximately 1 tablespoon may be used for added depth while keeping the bourbon flavor subtle.
Fold the chopped pecans gently into the mixture until they are distributed evenly. Add a small pinch of sea salt, if desired.
As soon as the partially baked crust is removed from the oven, pour the prepared pecan filling evenly over its surface. Carefully spread the mixture toward all edges of the pan.
If using chocolate chips, scatter the ½ cup evenly across the top of the filling.
Return the pan to the 350°F oven and continue baking for 25–30 minutes. The filling should appear set around the edges while retaining a slight movement in the very center when the pan is gently shaken.
The surface should become golden brown, and the outer edges of the filling may begin to pull away slightly from the sides of the pan.
Place the pan on a wire cooling rack and allow the pecan pie bars to cool completely. This generally requires about 2 hours and allows the filling to firm sufficiently for clean slicing.
Once fully cooled, grasp the parchment paper overhang and carefully lift the entire slab from the pan. Transfer it to a cutting board.
Slice the slab into squares. For generous portions, cut approximately 2-inch squares. Wipe the knife with a damp cloth between cuts to maintain neat, defined edges.