Place graham cracker crumbs on a plate.
In small bowl whisk together eggs, milk, vanilla and salt.
Dip the both sides of each slice of bread into the egg mixture, then press both sides into the graham cracker crumbs.
Heat pan/skillet and melt 1/2 Tbsp of butter.
Cook each slice of bread until browned and crispy.
While still hot, place a piece of chocolate, then marshmallows, then cap with a second slice of bread on top. Allow to cook another minute or so to allow everything to melt.
Drizzle with chocolate syrup and enjoy.