Preheat oven to 400°F (200°C).

Cut butternut squash in half, scoop out seeds, and place cut-side down on a baking sheet.

Roast for 45-60 minutes, or until tender.

While squash is roasting, heat olive oil in a large pot over medium heat.

Add onion and cook until softened, about 5 minutes.

Add garlic and cook for 1 minute more.

Scoop out roasted squash and add to the pot.

Pour in vegetable broth and bring to a simmer.

Use an immersion blender to blend the soup until smooth.

Stir in heavy cream, maple syrup, nutmeg, salt, and pepper.

Serve hot.