Preheat the oven broiler. Line a small pan with aluminum foil and lightly coat with cooking spray.
Break the graham crackers in half and lay 4 of the squares out on a serving plate. Break the candy bars in half and lay one piece on each of the graham crackers on the plate.
Arrange the marshmallows in a single layer in the prepared pan.
Broil the marshmallows until the tops brown, turn the marshmallows to brown the undersides. Keep a close eye on the marshmallows so they do not burn. They will brown very quickly.
Remove the marshmallows from the pan and place three on each of the chocolate squares. Top with the remaining graham cracker halves.
