Preheat oven to 375°.
Cut squash in half lengthwise. Remove seeds. Reserve seeds for toasting. Place squash, cut sides down, on a jelly roll pan coated with cooking spray.
Bake at 375° for 50 minutes or until skin pierces easily with a fork. Scoop out pulp; set aside. Reduce oven temperature to 325°.
To toast seeds, rinse seeds and pat dry. Place on a foil-lined baking sheet coated with cooking spray. Bake at 325° for 15 minutes or until crisp and lightly browned, stirring every 5 minutes.
Melt butter in a Dutch oven over medium- high heat. Add onion, pear, and ginger. Sauté 10 minutes or until tender. Add squash pulp and 1 can broth. Bring to a boil. Reduce heat; simmer, uncovered, 10 minutes.
Place mixture in a blender or food processor. Process in batches until smooth. Pour mixture through a strainer into a bowl, pressing with the back of a spoon.
Return soup to Dutch oven. Add 1 can broth, half-and-half, and next 5 ingredients. Cook over medium heat until thoroughly heated, stirring often. Spoon into serving bowls, and top with toasted seeds.