Stir chicken broth, sweet potatoes, baby carrots, onion, red curry powder, cinnamon, and ground ginger together in a slow cooker.
Cook on Low for 7 hours.
Pour soup into a blender no more than half full. Cover and hold lid in place. Pulse blender a few times before leaving on to blend. Puree in batches until smooth. Return pureed soup to slow cooker. Stir half-and-half and maple syrup into the soup; season with salt and pepper.