1. Preheat oven to 425°F and line baking sheets with parchment paper.

2. Peel and cube butternut squash into 2-inch uniform pieces.

3. Toss squash cubes with 1 tablespoon olive oil, salt, and pepper until evenly coated.

4. Arrange squash in single layer on prepared baking sheets without overcrowding.

5. Roast 25-30 minutes until edges are golden brown and flesh is fork-tender.

6. Heat remaining oil in large pot over medium heat while squash roasts.

7. Sauté onion until softened and lightly caramelized, about 8 minutes.

8. Add garlic and ginger, cooking until fragrant, about 2 minutes.

9. Add roasted squash to pot along with broth, thyme, and bay leaves.

10. Bring to boil, then reduce heat and simmer 15 minutes to meld flavors.

11. Remove bay leaves and thyme stems before blending.

12. Blend soup until completely smooth using immersion blender or regular blender in batches.

13. Stir in butter, cream if using, and adjust seasoning with salt, pepper, and nutmeg.

14. Reheat gently if needed, then serve hot garnished with sage and pumpkin seeds.