In a large pot over medium heat, warm the butter. Add the carrots, onions, garlic, scallions. Cook, stirring occasionally, until the vegetables begin to soften, about 7 minutes.
Add the cumin, cinnamon and cook, stirring frequently, for 1 minute. Add the pumpkin, honey, salt, pepper and broth, cover the pot and bring to a boil. Reduce the heat to medium-low and simmer for 25 minutes. Using an immersion blender, puree the soup until smooth.
Add the milk and heavy cream and cook for 5 minutes more. Ladle the soup into bowls and drizzle with cream. Serve warm.