Butternut Squash Lasagna Recipe

Ingredients

• 8 cups cubed butternut squash (from a 2 1/2 to 3-pound squash)
• 3 tablespoons extra-virgin olive oil, divided
• 1/2 teaspoon salt, divided
• 1/2 teaspoon ground black pepper, divided
• 1 cup whole milk ricotta cheese
• 3/4 cup grated Parmesan cheese, divided
• 1/2 cup milk, or more, as needed
• 1 teaspoon grated nutmeg
• 12 to 16 lasagna noodles
• 8 to 12 ounces mushrooms, cleaned and sliced (like portobello, button, or cremini)
• 4 medium garlic cloves, minced or grated
• 10 ounces baby spinach leaves
• 3 cups shredded mozzarella cheese, divided
• 3/4 teaspoon Italian seasoning
• Fresh basil leaves and Parmesan cheese, for garnish
• Steps to Make It
• Gather the ingredients.
• Preheat the oven to 400 F. Line a large rimmed baking sheet with foil, then lightly grease with oil or olive oil spray. 
• Place the butternut squash cubes on the prepared baking sheet, then toss with 2 tablespoons of olive oil, 1/4 teaspoon of salt, and 1/4 teaspoon of pepper. Spread into an even layer.
• Bake the squash until fork-tender, about 30 minutes. Remove from the oven and reduce the oven temperature to 375 F.
• Meanwhile, being a large pot of water to a boil over high heat. Once the water reaches a boil, generously salt the water.
• Transfer the squash to a food processor along with the ricotta cheese, 1/4 cup of Parmesan cheese, 1/2 cup of milk, and the nutmeg. Pulse until smooth. If the mixture is too thick, add a few more tablespoons of milk. Set aside.
• Add the lasagna noodles to the boiling water and cook as directed for al dente noodles. 
• While the pasta is cooking, heat the remaining tablespoon of olive oil in a large skillet over medium heat. Add the sliced mushrooms and sauté for 3 minutes. Season with the remaining 1/4 teaspoon of salt and 1/4 teaspoon of pepper, then add the garlic. Continue to cook until the mushrooms have released most of their moisture, about 3 minutes. Add the spinach and cook until wilted, 1 to 2 minutes. Remove the vegetables from the heat and set aside to cool slightly.
• Drain the noodles, then gently lay them out on a lightly oiled baking sheet or tray. Turn to coat in the oil to prevent from sticking.
• Butter or oil a 2 1/2 to 3-quart baking dish. Spread about one-third of the butternut squash mixture in the prepared baking dish, then top with 1/2 cup of the mozzarella cheese. Sprinkle with a dash of Italian seasoning.
• Top the butternut squash/cheese layer with 3 lasagna noodles—or 4 if the baking dish is wide.
• Drain any excess moisture from the mushroom and spinach mixture, Spoon half of the veggie mixture over the noodle layer, then top with another 1/2 cup of mozzarella cheese. Sprinkle with another dash of Italian seasoning.
• Top the veggie mixture with 3 lasagna noodles.
• Repeat steps 11 through 14 until you use the last layer of noodles.
• Top the last layer of noodles with the remaining one-third of butternut squash, then top with the remaining 1 cup of mozzarella cheese and remaining 1/2 cup of Parmesan cheese. Sprinkle with another dash of Italian seasoning.
• Cover the baking dish tightly with foil, not letting it rest on the cheese layer.
• Bake the lasagna, covered, for 35 minutes.
• Remove the foil and bake the lasagna until the cheese is melted and lightly browned, 10 to 15 minutes longer. 
• Let the lasagna cool for about 15 to 20 minutes before slicing and serving. Garnish with extra Parmesan cheese and basil leaves, if desired.
• Tips
• Roasting the butternut squash ensures a thick, less watery sauce, while the ricotta cheese gives it richness. If you substitute with steamed or canned butternut squash puréé, you may not need the milk.