1. Peel squash. Halve lengthwise. Remove seeds and discard. Cut squash into 3/4-inch pieces.
2. In a large saucepan, combine squash, broth, water, and cayenne pepper. Cook, covered, over medium heat for 20 minutes or until squash is tender.
3. Transfer one-fourth of the squash-and-broth mixture to a blender container. Carefully blend, covered, until smooth. Repeat until all of the mixture is blended.
4. Return blended mixture to large saucepan. Bring just to boiling. Immediately reduce heat. Simmer, uncovered, for 5 minutes. Add the margarine or butter, stirring until just melted.
5. Meanwhile, prepare the ravioli according to package directions. Drain. Ladle hot squash mixture into bowls. Divide cooked ravioli among bowls. If desired, drizzle with molasses.
< Make-Ahead: Prepare soup as directed, except do not add ravioli. Cool soup. Transfer to an airtight container. Store in the refrigerator up to 2 days or label and freeze for up to 2 months. To reheat, transfer frozen soup to a large saucepan. Cook, covered, over medium-low heat for 15 to 20 minutes or until heated through, stirring often. Cook ravioli as directed and serve with soup as directed.