Spread seed mixture evenly on a baking sheet lined with parchment paper and coated with cooking spray.
Bake at 300 for 15 minutes. Stir mixture; bake an additional 15 minutes.
Place parchment on a wire rack; cool pumpkinseed mixture. Break into small pieces; set aside.
Preheat oven to 35
Cut squash in half lengthwise; discard seeds and membrane.
Brush oil over cut sides of squash; sprinkle cut sides with 1/4 teaspoon salt.
Place squash, cut sides down, on a jelly-roll pan.
Bake at 350 for 1 hour and 20 minutes or until squash is tender. Cool slightly. Scoop out squash pulp from skins; discard skins.
Place squash pulp and broth in a blender.
Remove center piece of blender lid (to allow steam to escape); secure blender lid on blender.
Place a clean towel over opening in blender lid (to avoid splatters). Blend until smooth.
Pour pureed mixture into a medium saucepan; stir in 2 cups water and remaining 1/2 teaspoon salt. Cook over medium-high heat 5 minutes or until thoroughly heated. Top each serving with seeds.