This Butternut Squash Lasagna is layers upon layers of delicious homemade roasted butternut squash sauce with roasted garlic and a cheesy spinach mixture, all baked until golden with crispy edges and topped with fresh sage. Perfect for any dinner table, especially on holidays or serving a crowd!
Toss the cubed butternut squash with olive oil, salt, pepper, nutmeg, and cinnamon. Spread them in an even layer on a parchment paper lined baking sheet.
Cut the top ¼ off the bulb of garlic and drizzle it with olive oil then wrap it in aluminum foil. Add it to the baking sheet with the butternut squash.
Roast the garlic and squash for about 30-40 minutes until tender.
To a high powered blender or food processor, add the roasted butternut squash, heavy cream, and squeeze the roasted garlic out of the bulb. Blend until smooth.
In a medium bowl add the butternut squash puree and mix in the ricotta cheese.
Make the spinach and cheese mixture
Warm a sauté pan over medium heat. Add a little olive oil and the onions. Cook, stirring frequently, until soft and translucent - about 5-8 minutes.
In large bowl, add the thawed chopped spinach, sautéed onions, ricotta cheese, parmesan cheese, ½ of the mozzarella cheese, gruyere cheese, egg, salt, and pepper. Mix until combined.
Boil a large pot of water. Add the lasagna noodles and cook until al dente – a few minutes less than the box directions. Drain and set aside in an even layer to prevent sticking.
Assemble & bake
Lower the oven to 375℉.
Use a 9x13 or 10x7 baking dish / casserole dish. There's going to be 3 layers of noodles. First, put ¼ cup of sauce on the bottom of the dish. Then layer 3 noodles side by side.
Add ⅓ of the remaining sauce and spread to an even layer. Follow with ½ of the cheese mixture and spread to an even layer.
Then repeat – noodles, sauce, rest of the cheese.
For the final layer, add noodles, remaining sauce, and sprinkle the remaining mozzarella cheese on the top of the lasagna.
Cover the lasagna with aluminum foil and bake for 30 minutes, then remove the foil and bake for another 10 until lightly browned. Option to broil for a few minutes if desired. Top with fresh sage leaves if desired.