Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper.

Place the cubed butternut squash, quartered onion, and the whole head of garlic (cut side up) on the baking sheet. Drizzle generously with olive oil and season with salt and pepper.

Roast for 35-40 minutes until the squash is very tender and the edges are beautifully caramelized.

Transfer the roasted squash and onion to a large blender or soup pot. Squeeze the roasted garlic cloves out of their skins into the pot.

Add the vegetable broth, nutmeg, and cinnamon. Blend until completely smooth (using a standing blender or immersion blender).

Stir in the heavy cream and gently warm the soup over low heat. Serve garnished with a swirl of cream and roasted pumpkin seeds.