Form a large sheet of foil into a 5-in., ball. Take another very large sheet of foil and wrap around the foil ball to form a cone. Shape the small end into a point, curving upward. Generously spray the entire foil cone with cooking spray. Set aside.
Place oven rack in center of oven. Preheat oven to 400°F. Spray a baking sheet with cooking spray; place foil cone on prepared baking sheet, with curved tip up; set aside. Line another baking sheet with parchment paper; set aside.