Heat the oven to 425.
Break the two graham cracker sheets in half, then place the four squares on a parchment-lined metal baking sheet.
Top two of the graham cracker squares with one marshmallow each.
Top the remaining two graham cracker squares with the chocolate. The chocolate will melt and spread so don't cover the entire graham cracker squares with chocolate.
Bake the s'mores for 5 to 7 minutes, or until the marshmallows are lightly browned.
Carefully remove the s'mores from the oven, then let cool for one to two minutes on the baking sheet.
If using peanut butter, drizzle on top of the chocolate, to taste.
Place each chocolate covered graham cracker square on top of a marshmallow covered graham cracker, lightly pressing down.
Cool for another minute, then enjoy!
