Preheat your oven to 400°F (200°C).

Toss the butternut squash cubes with olive oil, salt, and pepper on a baking sheet. Spread them out in a single layer.

Roast in the preheated oven for 25-30 minutes, or until the squash is tender and caramelizing at the edges. Remove from the oven.

In a large pot over medium heat, heat an additional tablespoon of olive oil.

Add the chopped onion and sauté until it is soft and translucent, about 5 minutes.

Add the minced garlic, cinnamon, and nutmeg, and cook for another minute until fragrant.

Add the roasted butternut squash and broth to the pot. Bring to a simmer and let cook for 10-15 minutes to meld the flavors.

Using an immersion blender, purée the soup directly in the pot until smooth. Alternatively, you can blend the soup in batches using a regular blender. Be careful when blending hot liquids.

Stir in the coconut milk or heavy cream and heat through. Adjust seasoning with salt and pepper to taste.

If the soup is too thick, adjust the consistency with a bit more broth or water until you reach your desired thickness.

Serve the soup hot, garnished with your choice of toppings such as a dollop of crème fraîche, a sprinkle of toasted pumpkin seeds, fresh herbs, or a drizzle of olive oil.