- 1 small butternut squash, peeled, seeded, and cut into 1-inch cubes
- 1 cup homemade chicken stock, or canned low-sodium chicken broth, skimmed of fat
- 1 1/2 cups nonfat milk
- Freshly grated nutmeg
- Pinch of cayenne pepper
- 3/4 tablespoon coarse salt, plus more for water
- Freshly ground black pepper
- 1 pound elbow macaroni
- 4 ounces extra-sharp cheddar cheese, finely grated
- 1/2 cup part-skim ricotta cheese
- 4 tablespoons finely grated Parmesan cheese
- 2 tablespoons fine bread crumbs
- 1 teaspoon olive oil
- Olive-oil cooking spray
- Preheat oven to 375 degrees F. Combine squash, stock, and milk in a medium saucepan; bring to a boil over medium-high heat. Reduce heat to medium; simmer until squash is tender when pierced with a fork, about 20 minutes. Remove from heat. Mash contents of saucepan; stir in nutmeg, cayenne, and salt, and season with black pepper. Stir to combine.
- Meanwhile, bring a large pot of water to a boil; add salt. Add noodles; cook until al dente, according to package instructions, about 8 minutes. Drain, and transfer to a large bowl; stir in squash mixture, cheddar, ricotta, and 2 tablespoons Parmesan.
- Lightly coat a 9-inch-square baking dish (4 inches deep) with cooking spray. Transfer noodle mixture to dish. In a small bowl, combine breadcrumbs, the remaining 2 tablespoons Parmesan, and oil; sprinkle evenly over noodle mixture.
- Cover with aluminum foil, and bake 20 minutes. Remove foil, and continue baking until lightly browned and crisp on top, 30 to 40 minutes more. Serve immediately.