A comforting, vegetarian fall classic featuring layers of creamy butternut squash puree, savory spinach ricotta filling, and melted mozzarella.
Here in Austin, when the first hints of autumn arrive, I immediately switch from grilling to baking, and this Butternut Squash and Spinach Lasagna is my favorite way to celebrate the season. It is a stunning vegetarian main course that balances the natural, nutty sweetness of butternut squash with the earthy, savory notes of spinach and garlic. Unlike traditional meat lasagnas that rely on heavy red sauce, this recipe uses a luscious squash-ricotta mixture as the primary "sauce," resulting in a dish that is creamy, vibrant, and surprisingly lighter on the palate.
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The secret to this lasagna's unique creaminess is blending the butternut squash puree directly with the ricotta and milk. This creates a smooth, spreadable sauce that permeates the noodles as they bake, eliminating the need for a separate béchamel or heavy tomato sauce.
Why You'll Love This Recipe
- Sweet and Savory Balance: The sweetness of the squash and nutmeg pairs perfectly with the savory garlic and spinach.
- Two Distinct Fillings: Alternating layers of orange squash filling and green spinach filling create a beautiful visual effect when sliced.
- Creamy Texture: The double-ricotta method ensures every layer is moist and velvety.
- Fall Flavor Profile: Nutmeg, paprika, and basil bring warmth to the dish without overpowering the vegetables.
Ingredients
Butternut Squash Filling
- Butternut Squash Puree: 2 cups. You can roast a squash and puree it, or use canned pure pumpkin/squash (ensure it is not pie filling).
- Ricotta Cheese: 1 cup.
- Milk: ½ cup (plus more if needed for consistency).
- Seasoning: ¼ teaspoon salt (plus extra to taste) and ¼ teaspoon nutmeg.
Spinach Filling
- Spinach: 8 oz fresh spinach, cooked down to yield about 1 cup (or use frozen spinach, thawed and squeezed dry).
- Ricotta Cheese: 1 cup.
- Mozzarella Cheese: 1 cup shredded.
- Aromatics: 2 garlic cloves, minced.
- Seasoning: ¼ teaspoon salt and pepper to taste.
Assembly & Toppings
- Lasagna Noodles: 10 oz, cooked according to package instructions.
- Mozzarella Cheese: 1 ½ cups (or more) for layering and topping.
- Parmesan Cheese: ½ cup grated for the top.
- Spices: ¼ teaspoon each of Italian seasoning, paprika, and dried basil.
How to Make Butternut Squash and Spinach Lasagna
1. Prepare the Squash Filling
Preheat oven to 375°F. In a food processor or blender, combine the 2 cups of butternut squash puree, 1 cup of ricotta cheese, milk, salt, and nutmeg. Blend until smooth. The consistency should be creamy and spreadable. If it is too thick, add a splash more milk. Taste and adjust salt if needed.
2. Prepare the Spinach Filling
In a medium bowl, combine the cooked spinach (make sure excess water is squeezed out), 1 cup ricotta cheese, 1 cup shredded mozzarella, minced garlic, salt, and pepper. Mix thoroughly. Note: If you cooked fresh spinach with a little lemon juice, that adds a nice brightness, but it is optional.
3. Cook the Noodles
Bring a large pot of water to a boil. Cook the lasagna noodles according to the package instructions until al dente. Drain and rinse briefly under cold water to stop the cooking. If necessary, trim the noodles to fit your baking dish.
4. Assemble the Lasagna
Grease an 11 x 8.5-inch casserole dish (or standard 9x13, though layers will be thinner) with olive oil spray.
- Layer 1: Spread ⅓ of the butternut squash filling on the bottom of the dish. Sprinkle lightly with mozzarella. Top with a layer of noodles (do not overlap).
- Layer 2: Spread ½ of the spinach filling over the noodles. Top lightly with mozzarella. Top with a layer of noodles.
- Layer 3: Spread another ⅓ of the butternut squash filling. Sprinkle lightly with mozzarella. Top with a layer of noodles.
- Layer 4: Spread the remaining half of the spinach filling. Top lightly with mozzarella. Top with a layer of noodles.
- Top Layer: Spread the remaining ⅓ of the butternut squash filling over the final layer of noodles.
5. Bake
Top the lasagna generously with the remaining mozzarella (about ½ cup) and the ½ cup of Parmesan cheese. Sprinkle the cheese with Italian seasoning, paprika, and basil.
Cover the dish with foil and bake for 30 minutes. Remove the foil and bake for an additional 10 minutes until the cheese is bubbly and slightly browned.
Common Mistakes to Avoid
- Watery Spinach: If using frozen or fresh cooked spinach, you must squeeze out as much water as possible. Excess water will seep out during baking and make the lasagna soupy.
- Overcooking Noodles: Boil the noodles only to al dente. They will continue cooking in the oven. If they are too soft before baking, they will turn to mush.
- Dry Squash Filling: If your squash puree is very thick (like canned pumpkin), be sure to add enough milk so that the mixture spreads easily like a thick sauce.
Tips and Tricks for Success
Using Canned Puree If you don't have time to roast a squash, canned pure butternut squash or even canned pure pumpkin works excellently and saves over an hour of prep time.
No-Boil Option You can use oven-ready (no-boil) lasagna noodles to save time. However, you must ensure your squash filling is slightly more liquid (add an extra ¼ cup milk) to ensure the noodles hydrate properly.
Let it Rest Allow the lasagna to rest for 10-15 minutes after taking it out of the oven. This allows the cheese and fillings to set, making it much easier to slice into clean squares.
Variations
- Add Sausage: For meat eaters, crumble cooked Italian sausage into the spinach filling layer.
- Fresh Herbs: Swap the dried basil for fresh sage leaves fried in butter for a gourmet topping that pairs beautifully with squash.
- Gluten-Free: Use brown rice lasagna noodles (like Tinkyada brand) to make this dish entirely gluten-free.
How to Serve
This lasagna is rich and filling. Serve it with a crisp green salad with a sharp balsamic vinaigrette to cut through the creaminess. A side of garlic bread is always a welcome addition.
Make Ahead and Storage
Make Ahead: You can assemble the entire lasagna, cover it tightly, and refrigerate it for up to 24 hours before baking. You may need to add 5-10 minutes to the covered baking time if starting from a cold fridge.
Storage: Store leftovers in an airtight container in the refrigerator for up to 4 days.
Freezing: This lasagna freezes well. Bake it, let it cool completely, then freeze in individual portions.
Recipe Notes / What I Learned
I learned that nutmeg is the unsung hero of this dish. Even a small amount ($¼$ teaspoon) enhances the natural sweetness of the squash and makes the dish smell incredible while baking. Don't skip it!
Nutrition Snapshot
Estimated per serving (6 servings): 450 calories, 22g fat, 25g protein, 38g carbohydrates.
Butternut Squash and Spinach Lasagna
Equipment
- Food processor
- Large pot
- Casserole dish 11 inches x 8.5 inches
Ingredients
Group: Butternut Squash Filling
- 2 cups butternut squash puree pre-cooked, about half of a squash
- 1 cup ricotta cheese
- ½ cup milk or more, if needed
- ¼ +⅛ teaspoon salt
- ¼ teaspoon nutmeg
Group: Spinach Filling
- 8 oz spinach cooked (yields 1 cup)
- 1 cup ricotta cheese
- 1 cup mozzarella cheese
- 2 cloves garlic minced
- ¼ teaspoon salt
- pepper to taste
Group: Other Ingredients
- 10 oz lasagna noodles cooked
- 1 ½ cups mozzarella cheese or more
- ½ cup Parmesan cheese for topping
- ¼ teaspoon Italian seasoning
- ¼ teaspoon Paprika
- ¼ teaspoon Basil
Instructions
- Preheat oven to 375 F.
- For this filling, you will need to have pre-cooked butternut squash puree. Using food processor, combine 2 cups of butternut squash puree with Ricotta cheese, milk, salt and nutmeg. Add more milk if needed (to make the butternut squash filling very creamy). Mix very well, taste and add more salt, if needed.
- Combine cooked spinach, Ricotta cheese, mozzarella, garlic, salt and pepper. Mix, taste, and add more salt and pepper, if needed.
Note: You can use lemon juice and lemon zest with the spinach if you like, which pairs nicely with butternut squash, but it is optional. - Bring a very large pot of water to boil, and cook lasagna noodles according to package instructions. Rinse in cold water, drain. Using knife, trim noodles to fit your baking dish (if necessary).
- Prepare a baking dish - I used a casserole dish 11 inches x 8.5 inches x 3 inches deep. Grease the lasagna dish lightly with olive oil spray. Spread ⅓ of butternut squash filling on the bottom of the dish. Sprinkle lightly with mozzarella cheese. Top with cooked lasagna noodles without overlapping (I used 3 noodles).
- Spread half of spinach filling over the noodles. Top lightly with Mozzarella cheese. Top with cooked noodles.
- Spread another layer (⅓) of butternut squash mixture, then sprinkle lightly with Mozzarella cheese. Top with cooked noodles.
- Spread the remaining half of spinach filling over the noodles. Top lightly with Mozzarella cheese. Top with the final layer of cooked noodles.
- Spread a generous amount of butternut squash filling (the remaining ⅓) over this final layer of noodles, sprinkle with grated Parmesan and remaining mozzarella cheese (about ½ cup of mozzarella). Generously sprinkle the cheese with Italian seasoning, paprika, basil.
- Cover the baking dish with foil and bake for 30 min. Remove foil and bake additional 10 minutes.
Notes
Nutrition
FAQs
Can I use frozen spinach?
Yes. Thaw a 10 oz box of frozen spinach and squeeze it very dry in a clean kitchen towel. It creates the perfect texture for the filling.
How do I make butternut squash puree?
Slice a squash in half lengthwise, remove seeds, roast at 400°F for 45-50 minutes until tender, then scoop out the flesh and blend until smooth.
Can I use cottage cheese instead of ricotta?
Yes, cottage cheese is a common substitute. Blend it first to smooth out the curds if you want a texture similar to ricotta
