Preheat oven to 350 degrees. Place squash in a large shallow baking dish. Drizzle with butter, and toss to coat. Cover with parchment-lined foil. Transfer to oven, and cook until tender, 25 to 30 minutes.
Meanwhile, clean seeds and transfer to a small baking sheet; bake until dried out. When dried, cook in 1 tablespoon olive oil in a medium skillet until golden. Season with salt and pepper. Transfer to a parchment paper-lined baking sheet, and let stand until cool.
Using an immersion blender or working in batches in a blender, puree squash until smooth. Stir in honey, salt, and nutmeg. Transfer to a serving bowl, and garnish with roasted seeds.