Step 1

Preheat oven to 375°F. Oil baking sheet. Place squash, cut side down, on baking sheet. Bake until squash is very soft, about 50 minutes. Using paring knife, remove peel from squash; discard peel. Cut squash into 2-inch pieces. Heat oil in heavy large pot over medium-low heat. Mix in onion, brown sugar, ginger, garlic and cinnamon. Cover pot and cook until onion is tender, about 15 minutes. Add squash and 5 cups chicken broth. Bring to boil. Reduce heat to medium-low. Cover and simmer 10 minutes. Discard cinnamon.

Step 2

Working in batches, purée soup in blender. (Can be prepared 1 day ahead. Cool slightly. Cover and refrigerate.) Return soup to pot. Season soup with salt and pepper. Bring to simmer, thinning soup with more broth if necessary. Ladle into bowls. Sprinkle with parsley and serve.