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 1/2 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 1/2 cups chicken broth. Bring just to simmering. Ladle soup into warm bowls. Garnish with parsley.