In a large heavy pot, melt butter over medium heat. Add onions and saute until translucent, about 5 minutes. Add curry powder and chili powder. Mix well. Cook, stirring occasionally, 5 minutes. Stir in 2.5 cups chicken broth, squash, apples, and salt and pepper to taste. Bring to a boil. Reduce heat. Cover and simmer 30-45 minutes until squash is very tender, stirring occasionally. Strain soup, reserving liquid. Puree vegetables in a food processor in several batches. In same pot, combine vegetable puree, reserved cooking liquid, cream, and 2.5 cups chicken broth. Bring just to simmering. Ladle soup into warm bowls. Garnish with parsley.