Line a baking sheet with parchment paper. Preheat oven to 350 degrees.
Place graham crackers on the baking sheet in one layer leaving space between the crackers.
Layer chocolate, jam and marshmallows on top of the graham crackers.
Bake until marshmallows are puffy and toasted.
Remove pan from oven and top each stack with another graham cracker. Press down gently to form a sandwich of goodness. Serve immediately.