Preheat your oven to 350 °F (177 °C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang for easy removal.

In a medium bowl, whisk together the flour, powdered sugar, and salt for the crust. Add the softened butter and vanilla extract; use a pastry cutter or your fingers to work the mixture until it comes together in a smooth dough. Press this dough evenly into the prepared pan. Bake for 12-14 minutes until the edges begin to turn light golden. Remove from oven and set aside while you prepare the topping.

In a saucepan over medium heat, melt the butter for the topping. Stir in the maple syrup and salt, and bring to a gentle boil. Let the mixture simmer for 1 minute (bubbles will thicken slightly) then remove from heat.

Whisk the eggs and vanilla extract in a small bowl, then gradually stream the hot maple mixture into the eggs while whisking continually (tempering) to avoid scrambling. Once fully combined, stir in the toasted pecans.

Pour the maple-pecan mixture evenly over the baked crust. Spread gently so the pecans distribute evenly. Return to the oven and bake for 18-20 minutes, or until the topping is set at the edges and slightly jiggly in the centre. The top should glisten but not be liquid.

Remove from oven and allow the pan to cool on a wire rack for 15 minutes, then transfer to the refrigerator and chill for at least 1 hour before slicing. Use the parchment overhang to lift the bars out and cut into 16 squares. Store in an airtight container.