Preheat oven to 350°F (175°C). Line a 9×13-inch pan with parchment, leaving overhang. Mix flour, powdered sugar, and salt. Cut in cold butter until crumbly, press into pan, and bake 15 minutes until golden at edges.

Meanwhile, spread pecans on a baking sheet and toast in the same oven 8 to 10 minutes, stirring once, until fragrant. Cool.

Whisk melted butter, brown sugar, corn syrup, eggs, vanilla, and salt until smooth. Stir in toasted pecans.

Pour filling over the hot crust, spread evenly, and bake 25 to 30 minutes until edges are set and the center jiggles slightly.

Cool completely in the pan on a wire rack. Lift out using the parchment, place on a cutting board, and slice into 16 bars.