Preheat oven to 325 degrees F.

To make the crust, add the graham cracker crumbs, sugar, and salt to a large bowl and stir to combine. Add the melted butter and stir until well combined and crumbly.

Pour the mixture into a 9-inch deep dish pie pan and spread the crumbs around so that they are evenly dispersed. Press the crumbs into the bottom and up the sides of the pan.

Bake for 8-10 minutes, then set aside to cool.

To make the filling, whisk the cornstarch, sugar, and salt together in a medium-sized saucepan.

Add the egg yolks, milk, and heavy cream and whisk to combine.

Heat over medium heat while whisking constantly until the mixture starts to bubble around the edges and thickens to a pudding-like consistency.

Remove mixture from the heat and stir in the chocolate, butter, and vanilla extract. Stir until combined and the mixture is smooth.

Pour mixture into the prepared pie crust. Smooth the top and refrigerate for 5-6 hours until cooled and firm.

Preheat oven to 350 degrees F. Place regular-sized marshmallow halves around the top of the pie, filling in the space with mini marshmallows.

Bake for 3-4 minutes or until marshmallows are puffy, then broil on low for 2-4 minutes until browned as desired.

Serve warm or cooled, according to preference. Store leftovers in the fridge.