1Preheat your oven to 350* and prepare a baking sheet pan with parchment paper or aluminum foil. Arrange the graham crackers in a single layer on the pan.
2In a medium saucepan, melt the butter with the brown sugar over medium heat, stirring constantly until the mixture begins to bubble, boil for 3-5 minutes while stirring. Remove the saucepan from heat, then add the vanilla extract, salt, and pecans to the sugar mixture. Stir to combine.
3Pour the pecan mixture evenly over the top of the graham crackers, using a spatula to spread it out so all the crackers are covered.
4Bake in the oven until the caramel topping is bubbling.
5Let the bark cool completely to room temperature on the baking sheet, then break it or slice it into smaller pieces for serving.