Preheat the oven to 375 degrees and line a baking sheet with parchment paper.

Lightly flour a work surface and slightly roll out one sheet of puff pastry into a 10x11 inch rectangle. Cut into 6 triangles, using the fold lines as a guide. Transfer to the prepared baking sheet. Repeat with the remaining puff pastry and set aside.

Working with the pastries on the baking sheet, spread about 1 teaspoon of peanut butter on each pastry leaving about ¼-½ inch border all around the edges. Top with graham cracker, using ¾ a sheet of graham cracker for each pastry. You’ll need to break the graham cracker into small rectangles to fit within the border. Next, add enough chocolate to cover the graham cracker.

In a small bowl, mix together the egg and water to create an egg wash. Brush the edges of each pastry with egg wash and place the remaining 6 pastry rectangles on top. Use a fork to seal the edges, then brush the tops with egg wash.

Bake for 15 minutes until lightly golden brown, then you’re going to add marshmallows to the top. Remove the pastries from the oven and spread a small amount of peanut butter over the top of each puff pastry, just enough to help the marshmallows stick. Top each pastry with about ¼ cup of marshmallows. Return to the top rack of the oven and broil for about 1 minute until the marshmallows are golden brown.

Remove from the oven and let cool briefly before enjoying warm.