01 -
Preheat the oven to 350°F. Line a rimmed half-sheet pan with parchment paper or foil, then arrange the graham crackers in a tight single layer, breaking pieces as needed to fill the pan.
02 -
Combine the butter, brown sugar, and fine salt in a medium saucepan over medium heat. Stir until melted, then bring to a steady boil.
03 -
Once the mixture is bubbling steadily, cook for 2 full minutes while stirring and scraping the bottom of the pan. Remove from the heat.
04 -
Stir in the vanilla and chopped pecans. The mixture will bubble up slightly, so stir carefully.
05 -
Pour the hot pecan mixture over the graham crackers. Spread it evenly with a heatproof spatula, covering most of the crackers.
06 -
Bake for 9-11 minutes, until the topping is bubbling all over and the pecans smell toasted. Sprinkle with flaky salt if using.
07 -
Let the bark cool completely at room temperature until firm, about 45-60 minutes. Break into pieces and store airtight.