Preheat your oven to 400°F. Line a jelly roll pan (10"x15"x1") with aluminum foil. Lightly spray the foil with nonstick cooking spray.Arrange the graham crackers touching each other in a single layer on the prepared baking sheet; set aside.
In a medium saucepan, combine butter and brown sugar over medium high heat. Bring to a boil and cook, stirring constantly, for 4-5 minutes.Pour the mixture evenly over the graham crackers. Carefully spread to cover as many crackers as you can.
Bake for 5 minutes then turn off the oven and remove the pan.
Top with chopped pecans and allow to sit at room temperature for 30-minutes. Place in the fridge to harden. Break into pieces and serve!
Keyword christmas treat, graham cracker toffee bars