Preheat the oven to 400°F (200°C). Toss the squash cubes with 1 tablespoon of the olive oil on a large rimmed baking sheet, then spread them in a single layer. Roast for 25 to 30 minutes, until the squash is fork-tender and caramelized at the edges.

While the squash roasts, heat the remaining 1 tablespoon olive oil in a large pot or Dutch oven over medium heat. Add the onion and carrots, then cook for 6 to 7 minutes until softened.

Next, add the garlic, cinnamon, and nutmeg, and cook for 1 minute until fragrant.

Add the roasted squash to the pot, then pour in the vegetable broth. Bring the soup to a boil, then lower the heat and simmer for 10 minutes.

Use an immersion blender to puree the soup directly in the pot until completely smooth, about 2 minutes. If using a stand blender, work in batches and blend carefully, then return the soup to the pot.

Stir in the heavy cream and maple syrup, then season with salt and pepper. Simmer over low heat for 5 more minutes to heat through. Adjust seasoning as needed.

Ladle into bowls and garnish with toasted pepitas and fried sage leaves if desired. Serve hot.