Preheat your oven to 175°C (350°F) and line the bottom of your 8-inch square pan with parchment paper, leaving overhang for easy removal.
In a mixing bowl, combine the flour and brown sugar. Pour in the melted butter and stir until the mixture resembles coarse crumbs.
Press the crumbly mixture evenly into the prepared pan to form the crust. Bake for 15 minutes until lightly golden and fragrant.
While the crust bakes, toast the pecans in a dry skillet over medium heat until fragrant and darker, about 3-4 minutes. Let them cool slightly, then chop coarsely.
In a saucepan, heat the maple syrup over medium heat until it begins to simmer, about 2-3 minutes. Add the heavy cream, vanilla extract, and a pinch of sea salt, stirring gently until combined. Bring to a gentle boil and simmer for 2 minutes to thicken slightly.
Remove the syrup mixture from heat and stir in the toasted pecans. Pour the pecan caramel over the warm crust, spreading it evenly with a spatula.
Bake the assembled bars for another 20-25 minutes until bubbling, caramelized, and the pecans are golden brown. The topping should crackle slightly when ready.
Remove the pan from the oven and allow the bars to cool completely on a wire rack for about 1 hour. This helps set the caramel and makes slicing easier.
Once cooled, use the parchment paper overhang to lift the bars out of the pan. Slice into squares with a sharp knife for clean, neat edges.
Serve the bars at room temperature or slightly warmed, enjoying the crunch of toasted pecans contrasted with the soft, buttery crust and sticky caramel topping.
