Break the graham crackers into squares. Cut the prepared marshmallows into similarly-sized cubes.
Melt the chocolate chips using a double boiler, with water in the bottom pot and chocolate chips in the top pot, simmering until the chocolate chips have completely melted.
Dip each marshmallow in melted chocolate, then press onto a graham cracker. Using a spoon or spatula brush additional melted chocolate on a second graham cracker and place on top of the marshmallow. Repeat with all marshmallows. Set aside to let the chocolate cool and harden. Can be stored up to a week in a sealed container.