Line a 9x13" pan with foil. Place graham crackers in a single layer over the foil. You may have to break the graham crackers to fill in spaces.
In a saucepan over medium heat, melt the butter. Add the brown sugar and cook until the sugar dissolves and it just begins to bubble.
Pour the sugar mixture evenly over the graham crackers.
Sprinkle peanut butter chips over the sugar mixture.
Place the baking sheet in the oven and preheat to 350 degrees. Check every 4 minutes. When the peanut butter chips look a little melted remove from oven.
With a spatula carefully spread the peanut butter chips evenly over the sugar mixture. The peanut butter chips won't melt completely on their own like chocolate chips.
Sprinkle the candy with the chopped pecans.
Chill for at least an hour (overnight works best)
Break candy into pieces and store in an airtight container.