Preheat your oven to 350°F (175°C) and prepare a 9x13-inch baking dish by lining it with parchment paper.

In a mixing bowl, combine the all-purpose flour, brown sugar, and salt, stirring until well combined.

Add cold, diced unsalted butter and mix until coarse crumbs form. Press into the baking dish and bake for 15–18 minutes.

While the crust is baking, whisk together the maple syrup, brown sugar, eggs, vanilla extract, and a bit of flour until smooth.

Fold in chopped pecans, ensuring they're evenly distributed.

Once the crust is golden, pour the filling over it, spreading evenly, and bake for 30–35 minutes.

Allow the bars to cool in the pan on a wire rack before slicing.

Sprinkle with flaky sea salt before serving.