Heat oven to 400°F (200°C). Toss squash with 1 tablespoon oil, salt, and pepper on sheet.
Roast 35-40 minutes, turning halfway, until tender and lightly caramelized.
Meanwhile, heat remaining oil in large pot over medium; cook onion 5 minutes until softened.
Cook garlic and apple 2-3 minutes until fragrant.
Add roasted squash, broth, cinnamon, and nutmeg. Boil; reduce heat and simmer 10 minutes.
Immersion-blend completely smooth and creamy, or use regular blender in batches.
Add cream and maple syrup; heat through 2-3 minutes without boiling.
Taste; adjust seasoning. Serve hot with optional toasted pumpkin seeds and cream drizzle.