In a small bowl, combine the graham cracker crumbs, melted butter and sugar. Stir until the crumbs are damp and hold together. Transfer the crumbs to a 9-inch pie pan. Using the back of a spoon, press the crumbs into the bottom of the pan and up the sides.
Spoon the chilled pudding into the baked pie crust. Cover with mini-marshmallows.