In a medium pot over medium heat, melt the butter and olive oil.
Add the onion and sautué until translucent, 3 to 4 minutes. Add the garlic and sautué for 1 minute more.
Add the carrots, broth and the potatoes, reduce the heat to low, cover and simmer for 15 minutes. Add the spinach, and continue to simmer for about 10 minutes more.
Using a food processor or blender, process the soup to a smooth puree. Return the soup to the pan. Add the cream and season with salt and pepper.
Ladle the soup into bowls. Drizzle with cream and serve immediately.