Mix together 2 cups of all-purpose flour and a pinch of salt in a large bowl. Cut in 1 cup of cold, salted butter until it resembles coarse crumbs. Gradually add 5 tablespoons of ice cold water until the dough comes together. Chill for at least 3 hours.

In a medium saucepan, combine 1 cup of milk chocolate chips, ¼ cup of milk, ¼ cup of cocoa powder, a pinch of salt, and 1 teaspoon of vanilla extract. Stir continuously until thickened, about 4-5 minutes. Remove from heat, stir in 2 tablespoons of butter until melted, and let cool.

Roll out the chilled dough to about ¼ inch thick and cut into rectangles measuring 3x4.5 inches. Place on a parchment-lined baking sheet and chill again for 15 minutes.

Preheat the oven to 375°F (190°C). Take half the rectangles, spread 1 tablespoon of chocolate fudge filling on each, brush edges with an egg wash, seal with remaining rectangles, crimp edges, puncture holes, and bake for 19-24 minutes until golden brown.

Prepare the marshmallow cream by beating 3 egg whites and ¾ cup of granulated sugar with cream of tartar over simmering water until dissolved. Transfer to a stand mixer and beat until glossy peaks form, then add 1 teaspoon of vanilla.

Once cooled, spread reserved chocolate fudge filling on top, pipe marshmallow cream generously, toast lightly with a kitchen torch, and sprinkle extra graham cracker crumbs on top.