How to Make It
Preheat the oven to 350°. Season the kabocha, butternut and acorn squashes with salt and pepper and lay them cut side down on 2 large rimmed baking sheets. Pour 1 cup of water onto each baking sheet, cover the squash with foil and bake for about 1 hour, or until tender. Let cool slightly, then scoop the flesh into a bowl. Keep the oven on.
In a large saucepan or casserole, melt 4 tablespoons of the butter. Add the onion and cook over moderately low heat, stirring occasionally, until softened, about 8 minutes. Add 1/4 teaspoon each of the cardamom and nutmeg and 1/8 teaspoon each of the ginger and cloves and cook, stirring, until fragrant, about 2 minutes. Add the chicken stock and bring to a boil over moderately high heat. Add the squash flesh and heavy cream and simmer over moderate heat for 5 minutes. Working in batches, puree the soup in a food processor and return to the pan. Season with salt and pepper and keep warm over very low heat.
Meanwhile, on a large rimmed baking sheet, toss the pieces of bread with the 3 tablespoons of melted butter. Spread the bread out and bake for about 8 minutes, or until golden brown.
In a small bowl, combine the crème fraîche with the remaining pinches of cardamom, nutmeg, ginger and cloves and season with salt and pepper. Ladle the soup into bowls, dollop with crème fraîche and croutons and serve.