Bring chicken stock and whipping cream to boil in heavy medium pot. Whisk in canned pumpkin, brown sugar, cumin, chili powder, coriander and nutmeg. Reduce heat to medium and simmer until soup thickens slightly and flavors blend, about 15 minutes. Season to taste with salt and pepper. (Soup can be prepared up to 1 day ahead. Cool. Cover and refrigerate. Rewarm over medium-low heat, whisking occasionally.) Ladle soup into bowls. Garnish each serving with cheddar cheese and cilantro and serve.