Preheat broiler to high.
Place the graham crackers on a baking sheet
Cut each marshmallow in half. Top each graham cracker with two marshmallow pieces. Place under the broiler for 2 minutes. Keep a close eye on it so it doesn't burn.
Add the chocolate bars to a small bowl. Melt in the microwave at 50% power stirring occasionally.
Drizzle the chocolate over the graham crackers.