Preheat oven to 400°.
Cut the squash in half lengthwise; remove and discard seeds. Place squash halves, cut sides down, on a foil-lined jelly roll pan coated with cooking spray. Remove white papery skin from the garlic head (do not peel or separate the cloves). Wrap garlic head in foil. Place garlic on pan with squash. Bake at 400° for 30 minutes or until squash is tender. Cool slightly. Scoop out the pulp from squash, and discard skins. Separate garlic cloves; squeeze to extract garlic pulp. Discard skins.
Place squash, garlic, juice, salt, and cheese in a food processor; process until smooth. Spoon mixture into a bowl, and sprinkle evenly with nuts. Serve with baguette slices.