Heat olive oil in a large pot over medium heat. Add the chopped onion and cook until softened, about 5 minutes.
- Add the minced garlic and grated ginger, cooking for an additional minute until fragrant.
- Stir in the curry powder, turmeric, and cinnamon, allowing the spices to toast for 1-2 minutes.
- Add the pumpkin puree, coconut milk, and vegetable broth, stirring to combine. Bring the mixture to a simmer.
- Let the soup simmer for 20 minutes, stirring occasionally to prevent sticking.
- Use an immersion blender to blend the soup until smooth. Alternatively, transfer the soup to a blender in batches and blend until creamy.
- Season with salt and pepper to taste.
- Serve hot, garnished with fresh cilantro, pumpkin seeds, or a dollop of sour cream or yogurt.