First, you need just a basic graham cracker crust. (Aunt Terry's Pumpkin Chiffon Pie one would work awesome http://leefam1946.blogspot.com/2012/11/pumpkin-chiffon-pie.html. Let the crust set in the fridge for at least 5-10 mins. Then grab your favorite vanilla ice cream (let it set out a soften so, it is easier to use). Once, crust has set fill with the ice cream. Then top the whole pie with small marshmallows.
Stick the pie back in the freezer to harden and cover with plastic wrap. Then when you are ready to serve grab your strongest lighter- we use a Creme' Brulee torch but any lighter should work.