How to Make It
In a large pot, melt the butter over moderate heat. Once the butter is just beginning to brown, add the onion and sauté for 5 minutes. Add the garlic, sugar, pepper, cinnamon, nutmeg and cayenne pepper and cook for 3 minutes. Add the pumpkin puree and broth, stirring to incorporate, then season with the salt and bring the mixture to a boil. Reduce the heat to low and simmer for 20 minutes. Stir in the cream and let the soup cool for 10 minutes.
Meanwhile, preheat the oven to 400º. Toss the baguette pieces with the olive oil, rosemary and salt and spread them evenly on baking sheet. Bake for 10 minutes, or until golden brown. Remove from the oven and set aside.
Once the soup has cooled slightly, transfer it to a blender (or use an immersion blender in the pot) and puree until smooth. If needed, add additional water or broth to reach desired the consistency. Return the mixture to the saucepan. Serve warm and garnish with the rosemary croutons.