Halve squash; remove seeds. Cut each piece in half. Place a steamer basket in a large saucepan or Dutch oven; add broth to saucepan. Bring to boiling; place squash in steamer basket.
Cover and steam for 25 to 30 minutes or until squash can be pierced easily with a fork. Carefully remove steamer basket from saucepan. Reserve steaming liquid in saucepan.
Using a spoon, scoop squash pulp out of the peel; discard peel. Place squash pulp in a blender container or food processor bowl. Cover and blend or process until mixture is smooth, adding as much of the reserved liquid as necessary.
Stir pureed squash into remaining reserved liquid in the saucepan; stir in ginger, salt, pepper, and cinnamon. Bring mixture to boiling. Reduce heat and stir in half-and-half or cream. Heat through. If desired, garnish each serving with a dollop of sour cream and chives. Makes 4 side-dish servings.