Preheat the oven broiler to high.
Arrange four graham cracker halves on a parchment-lined baking sheet.
Place one chocolate square on each cracker half.
Position one marshmallow on top of the chocolate.
Place the baking sheet under the broiler for 45 to 90 seconds until the marshmallows are toasted and golden.
Remove from oven and immediately sprinkle crushed peppermint over the hot marshmallows.
Top with the remaining graham cracker halves and press lightly to fuse the ingredients.