Prepare the Dough: In a large stand mixer, combine lukewarm milk, water, instant yeast, and granulated sugar. Let sit for 5 minutes until bubbly. Gradually add flour, melted butter, and salt, mixing until soft. Knead for 6-8 minutes. Allow to rest in a greased bowl for 15 minutes.

Make the Filling: Heat cocoa powder, whipping cream, chocolate chips, and sugar in a saucepan over low heat. Stir until smooth. Cool slightly, then add melted butter, vanilla extract, and graham cracker crumbs.

Assemble the Rolls: Roll the dough into a 10” x 16” rectangle. Brush with melted butter, spread the filling, and sprinkle with graham cracker crumbs. Roll tightly and slice into 8-10 pieces.

Bake: Preheat oven to 350°F (175°C). Arrange rolls in a greased baking dish with space between. Bake for 25-28 minutes until golden. Let cool in the pan for 10 minutes.

Create Marshmallow Meringue: In a double boiler, whisk egg whites and sugar until warm. Whisk until stiff peaks form, adding cream of tartar and vanilla. Meringue should be glossy.

Finish the Rolls: Spread meringue over warm rolls and toast with a kitchen torch or broiler until golden. Cool slightly before serving.