Prep the pan: Heat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment, leaving overhang for easy lifting. Lightly grease the parchment.

Make the shortbread crust: In a bowl, cream 1 cup (2 sticks) softened unsalted butter with 1/2 cup granulated sugar and 1/2 teaspoon salt until smooth. Mix in 2 cups all-purpose flour until crumbly and evenly moistened.

Press and par-bake: Press the dough evenly into the pan. Dock with a fork a few times. Bake 15–18 minutes until lightly golden at the edges. Set aside while you make the filling.

Toast the pecans: Spread 2 1/2 to 3 cups pecans on a sheet pan and toast in the oven for 7–8 minutes, until fragrant. Cool slightly, then roughly chop if you prefer smaller pieces.

Cook the maple filling: In a saucepan, melt 1/2 cup (1 stick) unsalted butter. Whisk in 1/2 cup light brown sugar, 3/4 cup pure maple syrup, and a pinch of salt. Bring to a gentle simmer over medium heat and cook 1–2 minutes, whisking, until glossy and slightly thickened. Remove from heat and cool 5 minutes.

Add eggs and vanilla: Whisk 3 large eggs in a separate bowl. Slowly stream in the warm maple mixture while whisking constantly so the eggs don’t scramble. Stir in 2 teaspoons vanilla extract and a pinch of cinnamon if using.

Combine with pecans: Stir the toasted pecans into the filling until evenly coated.

Bake the bars: Pour the mixture over the warm crust and spread evenly. Bake 22–28 minutes, until the center is set but still slightly jiggly and the top looks shiny.

Cool and chill: Let the pan cool on a rack until room temperature, then chill at least 2 hours. This step helps the bars slice cleanly.

Slice and finish: Lift out using the parchment. Cut into 24 squares or 18 larger bars. Sprinkle with flaky sea salt if you like a sweet-salty finish.