Combine the cinnamon and sugar in a small bowl and set aside. Spread the melted butter over the pie crust and sprinkle evenly with the cinnamon sugar. Bake until golden brown, 8 to 10 minutes. Let cool completely, then crumble and set aside.
Build your sundaes starting with the pumpkin ice cream, dipping the scoop in a mug of hot water if necessary. Top with the pie crust crumbles, caramel sauce and candied pecans. Serve immediately.