Make the crust. In a bowl, stir together graham cracker crumbs, sugar, and salt. Pour in melted butter and mix until the crumbs look like wet sand and hold when pressed.

Press and bake. Firmly press the mixture into the bottom and up the sides of a 9-inch pie dish. Bake at 350°F (175°C) for 8–10 minutes, until fragrant and lightly set. Let it cool while you make the filling.

Heat the cream. In a small saucepan over medium heat, warm the heavy cream until it’s steaming and just starting to bubble around the edges. Do not boil.

Make the ganache filling. Place chopped chocolate and butter in a heatproof bowl. Pour the hot cream over the chocolate, let sit 2 minutes, then add vanilla and salt. Stir gently until smooth and glossy.

Fill the crust. Pour the chocolate filling into the cooled crust. Smooth the top with a spatula. Chill in the fridge for at least 2 hours, or until set.

Add the marshmallows. Once set, cover the top of the pie with mini marshmallows in an even layer, leaving no gaps. Pack them snugly for a pretty finish.

Toast the topping. Use a kitchen torch to toast the marshmallows until golden brown. If using a broiler, set the rack in the upper third, preheat the broiler, and watch closely—1–2 minutes is usually enough. Rotate the pie if needed for even color.

Finish and serve. Let the toasted marshmallows cool for 5–10 minutes to set slightly. Slice with a knife lightly coated in oil or warm water for cleaner cuts. Add extra crushed grahams or a chocolate drizzle if you like.