In a large pot, heat a little oil over medium heat. Add the onions and garlic and sauté until the onions are translucent, about 5 minutes.
Add the pumpkin, potatoes, carrots, broth, water, and spices to the pot. Bring the mixture to a boil, then reduce the heat to low and simmer for 20-30 minutes, or until the vegetables are very soft.
Use an immersion blender to purée the soup until smooth. Alternatively, you can transfer the soup to a blender or food processor and blend until smooth, working in batches if necessary.
Return the soup to the pot and heat over low heat until warmed through. Stir in the cream or coconut milk, if using. Taste and adjust the seasoning as needed.
Serve the soup hot, garnished with a sprinkle of chopped herbs or a drizzle of cream, if desired. Enjoy!