Preheat oven to 400°F (200°C). Toss cubed butternut squash with 1 tbsp olive oil, salt, and pepper. Spread on a baking sheet and roast for 25-30 minutes, until tender and slightly caramelized.
In a large pot, heat the remaining 1 tbsp olive oil over medium heat. Add onion, garlic, and ginger, and sauté until softened, about 5 minutes.
Add the roasted squash and vegetable broth to the pot. Bring to a boil, then reduce heat and simmer for 10 minutes.
Use an immersion blender to puree the soup until smooth. Alternatively, carefully transfer to a blender in batches.
Stir in the heavy cream and season with salt and pepper to taste.
Ladle into bowls, swirl with extra cream, and garnish as desired.
Notes
For a lighter version, substitute heavy cream with coconut milk or Greek yogurt. Customize with spices like nutmeg or cumin for extra flavor.