Preheat your oven to 200°C (400°F). Spread the chopped pumpkin on a baking sheet, drizzle with olive oil, and toss to coat evenly.
Roast the pumpkin in the oven for about 25-30 minutes until it’s tender and slightly caramelized around the edges.
While the pumpkin roasts, heat a large pot over medium heat. Add diced onion and cook, stirring occasionally, until translucent and fragrant, about 5 minutes.
Add minced garlic and ground cinnamon to the onions, cooking for another minute until aromatic.
Once the pumpkin is roasted and cool enough to handle, scoop it into the pot with the onion mixture.
Pour in the coconut milk and vegetable broth, then bring the mixture to a gentle simmer. Let it cook for 10-15 minutes to meld the flavors.
Use an immersion blender to blend the soup until smooth and velvety, or carefully transfer to a blender and purée until creamy.
Season with salt and pepper to taste, adjusting the flavor as needed.
Serve the soup hot, garnished with a drizzle of coconut milk or fresh herbs if desired.
