Heat the olive oil in a large pot over medium heat. Add the onion, salt, and several grinds of fresh pepper and sauté until soft; about 5 to 8 minutes. Add the garlic, ginger, cinnamon, and nutmeg. Stir and let cook until fragrant; about 1 minute. Make sure to scrape any golden bits of the bottom of the pan for extra flavor.
Add the butternut squash and broth. Bring to a boil, then reduce the heat to a simmer. Cook uncovered for 15-20 minutes or until the squash is tender.
Carefully ladle the soup into a blender, working in batches if necessary. Add the fresh mandarin orange juice and cashew cream. Blend until smooth. Taste and adjust seasoning as needed.
The soup can be served immediately or placed back on the stove top to simmer and thicken. Serve with a drizzle of cream, pumpkin seeds, salt and pepper.
Store leftover soup in an airtight container in the fridge for up to a week or in the freezer for three months.