01 - Set oven to 350°F (176°C) and allow to fully preheat.
02 - In a large mixing bowl, combine softened butter, cane sugar, and egg. Beat with an electric mixer until the mixture is smooth and creamy. Add flour, graham cracker crumbs, and baking powder, then mix until a sticky dough forms. Stir in vanilla extract until fully incorporated. Reserve for later.
03 - In the prepared graham crust, scatter half the mini marshmallows evenly, then gently spoon over half of the marshmallow creme. Microwave marshmallow creme for 5 to 7 seconds, if needed, to ease spreading. Layer the broken pieces of milk chocolate bars on top.
04 - Distribute the rest of the mini marshmallows and remaining marshmallow creme evenly over the chocolate layer.
05 - Crumble the reserved graham dough over the entire surface of the pie, leaving small areas where marshmallow may peek through. Sprinkle with milk chocolate chips.
06 - Bake on the middle rack for 20 to 25 minutes until the topping is golden brown and set.
07 - Remove pie from oven and allow to cool for at least 20 minutes before slicing and serving.