Preheat Oven:
Preheat oven to 350°F (175°C).
Prepare Crust:
In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Press mixture firmly into the bottom and slightly up the sides of a 9-inch pie pan. Bake for 8–10 minutes, then remove and let cool.
Make Chocolate Filling:
In a small saucepan over low heat, melt chocolate chips with heavy cream and butter, stirring until smooth. Remove from heat and stir in vanilla extract. Pour filling into cooled crust and smooth the top.
Prepare Marshmallow Topping:
Spread marshmallow fluff evenly over the chocolate layer. Optionally, sprinkle mini marshmallows on top.
Toast the Topping:
Using a kitchen torch, lightly toast the marshmallow topping until golden brown. Alternatively, place pie under the broiler for 1–2 minutes, watching carefully to prevent burning.
Chill and Serve:
Allow the pie to cool for 10–15 minutes, then refrigerate for at least 1 hour before slicing. Serve chilled or at room temperature.