Wash and dry the pumpkins.
Cut the pumpkins into slices (follow my video tutorial).
Preheat the oven to 425 F.
Place the pumpkin slices on the tray. Spread a layer of oil on both of the pumpkin surfaces.
Add the ground cinnamon, brown sugar and salt evenly.
Put the tray into the oven. Roast them until tender, usually around 30 minutes. You may toss them halfway to make sure they are roasted evenly on both sides.
Serve immediately.