Step 1: Preheat your oven to 350°F (175°C) and line a 9x9 inch square baking pan with parchment paper, ensuring there is some overhang on the sides for easy removal.
Step 2: In a medium bowl, combine the flour, granulated sugar, and 1/4 tsp salt. Cut in the cold, cubed butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
Step 3: Press the crust mixture firmly into the bottom of the prepared pan. Bake for 15-18 minutes, or until the edges are just lightly golden brown.
Step 4: While the crust is baking, prepare the filling by whisking the eggs, maple syrup, brown sugar, melted butter, vanilla extract, and 1/2 tsp salt in a large bowl until smooth.
Step 5: Stir the pecan halves into the filling mixture until they are evenly coated.
Step 6: Pour the pecan filling over the hot, par-baked crust, spreading the pecans evenly with a spatula.
Step 7: Return the pan to the oven and bake for another 25-30 minutes, or until the filling is set around the edges and only slightly jiggly in the center.
Step 8: Remove from the oven and allow the maple pecan pie bars to cool completely in the pan on a wire rack before refrigerating for at least 2 hours to set perfectly.