preheat oven to 350 fahrenheit. Line a 11x 7 x1 1/2 inch baking pan with parchment paper or lightly grease the pan and set aside.

in a medium saucepan melt butter, & chocolate over low heat. remove from heat, stir in sugar, eggs and vanilla until combined. stir in flour.

spread half the batter in the prepared pan. Top with graham crackers

sprinkle marshmallows on the graham crackers, do not let them touch the sides of the pan. Carefully spread the remaining batter on the marshmallows and graham crackers, covering them completely.

bake for 25 minutes or until set. Cool completely on a wire rack and cut into bars.