Peel and core the pumpkin. Peel the potatoes, carrots and onions as well. Cut the vegetables into pieces and place in a saucepan with the vegetable stock. Bring the whole thing to a boil and simmer for about 20 minutes.
Take the pot off the stove and puree the vegetables with a hand blender (possibly a potato masher). Season with salt, pepper and cinnamon to taste. Finally stir in the cream. Fresh baguette bread goes well with it.