Preheat oven to 350 degrees.
Place graham crackers in ungreased cookie sheet, single layer.
In a small saucepan, melt butter. Add brown sugar and pecans and cook 3 minutes, stirring constantly. Don't let it boil over.
Spread butter, sugar and nut mixture over the crackers, evenly.
Bake in preheated oven 10 minutes.
Immediately cut into 48 bars. Cool and store in airtight container. Enjoy!