Preheat the oven to 350°F (177ºC). Line an 8X8-inch baking pan with aluminum foil, extending the edges of the foil on one side, 2 inches. Rotate the pan and line it with a second sheet of aluminum foil perpendicular to the first, extending the edges of the foil 2 inches on the other ends. Spray the foil with nonstick cooking spray.
In the work bowl of a food processor, add the flour (1 cup), brown sugar (1/3 cup), pecans (1/4 cup), salt (1 teaspoon), and baking powder (1/4 teaspoon). Pulse ingredients about 5 times or until the mixture looks like coarse sand. Add the butter (6 tablespoons) and pulse again about 8-10 times. Pour the mixture into prepared baking pan and press in evenly. Bake in the preheated oven until the crust begins to brown, about 20 minutes.
Make the filling:
In a medium mixing bowl, mix together brown sugar (1/2 cup), melted butter (4 tablespoons), corn syrup (1/3 cup), bourbon (1 tablespoon), vanilla (2 teaspoons), and salt (1/2 teaspoon) until just combined. Whisk in the egg (1) just until incorporated.
Pour the filling mixture over the hot crust and then top evenly with pecans (2 cups).
Bake until the top forms cracks and is brown, 22-25 minutes. Cool on wire rack completely. Cut into bars.
Notes
Toast the pecans — always. Raw pecans taste flat in bars. A quick 8 minutes at 350°F brings out rich, buttery flavor that makes a huge difference.
Use the foil sling. Not optional! It keeps the edges sharp and ensures the bars lift out in one perfect slab.
Don’t rush the cooling. These bars need to cool completely to set. Cutting too early leads to oozing.
Choose light corn syrup. Dark corn syrup overwhelms the flavor and makes the bars overly sweet.
Try the bourbon. It doesn’t make the bars taste boozy — it deepens the caramel flavor beautifully.