Drain yams, reserving 1/2 cup syrup. Discard remaining syrup. Place yams in a blender. Add 1/2 cup syrup, broth, orange juice, and ginger. Blend 2 to 3 minutes or until smooth, stopping to scrape down sides.

Pour pureed mixture into a medium saucepan. Stir in coconut milk and remaining ingredients. Cook over medium heat, stirring often until soup is thoroughly heated. Ladle soup into bowls. If desired, drizzle additional coconut milk into soup. Yield 6 cups.