This Butternut Squash Lasagna is a cozy, veggie packed dish layered with roasted squash, caramelized onions, fresh spinach, and a creamy cheese sauce. It's hearty enough to serve as a main dish while still being light compared to traditional lasagna.
I love making this lasagna in the fall when squash is at it's peak, but it's a recipe I turn to year round when I want something comforting and wholesome. The layers of sweet roasted squash, golden onions, and nutty cheese make it feel special, like my own twist on classic lasagna.
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Why You'll Love This Recipe
Flavorful layers: roasted butternut squash and caramelized onions add natural sweetness and depth.
Vegetarian comfort: a hearty, meatless meal that's still filling and satisfying.
Creamy sauce: regular milk gives the bechamel-style sauce a velvety texture that ties the dish together.
Key Ingredients for Butternut Squash Lasagna
- Butternut squash: roasted with sage and garlic for a naturally sweet, savory base.
- Fresh spinach: lightly steamed and squeezed dry to layer into the lasagna.
- Caramelized onion: brings a deep, sweet-savory flavor that balances the squash.
- Low-fat milk: creates the rich creamys auce flavored with thyme and nutmeg.
- Monterey Jack cheese: melts into the sauce and creates a golden topping.
Ingredient Substitutions
- 2% milk: use fat free milk for a lighter sauce or half and half for extra richness.
- Monterey Jack: mozzarella or Fontina work beautifully for melting.
- Butternut squash: try acorn squash or sweet potatoes for similar flavor.
Variations on Butternut Squash Lasagna
- Add mushrooms: sauteed mushrooms make a nice earthy addition.
- Go spicy: add a layer of pepper jack cheese for a kick.
- Make it vegan: use plant-based milk and dairy free cheese
Tips for Perfect Butternut Squash Lasagna
- Caramelize slowly: cook onions low and slow until deep golden for the best flavor.
- Drain spinach well: excess water will make the lasagna soggy.
- Rest before serving: let the lasagna sit 10 minutes so the layers hold together.
How to Store and Reheat
Store leftovers in the refrigerator for up to 3 days. Reheat in the oven at 350°F, covered with foil, until warmed through. Individual portions can be microwaved, but the oven keeps the texture best.
Serve With...
This butternut squash lasagna pairs well with a crisp green salad topped with Homemade Ranch Dressing or Italian Vinaigrette. Try it with a side of Air Fryer Garlic Knots for a classic side.
More Easy Vegetarian Recipes
If you enjoyed this butternut squash lasagna, you might also like my Crustless Spinach Quiche, which is another veggie-forward comfort dish. For enchilada lovers try my Chipotle Butternut Squash Enchiladas with a little heat and a lot of flavor. For a lighter meal, try my Vegetarian Lentil Tostadas and for a seasonal twist, my Vegetarian Stuffed Zucchini.
When you make this recipe, please comment below and let me know what you think. I'd love it if you tag me on Instagram @grumpyshoneybunch or #grumpyshoneybunch so I can see your photos!
If you love this recipe, please leave a ⭐⭐⭐⭐⭐ rating
📖 Recipe
Butternut Squash Lasagna with Spinach and Caramelized Onions
Equipment
- Steamer
- Saucepan
- 8x8 Baking dish
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Ingredients
- 3 cups butternut squash peeled and cubed
- 1 tablespoons extra-virgin olive oil divided
- 1 tablespoon chopped fresh sage
- 6 cloves garlic chopped
- ½ teaspoon salt
- ¼ teaspoon fresh ground black pepper
- cooking spray
- 1 medium onion vertically sliced
- 2 tablespoons water
- 9 ounces fresh spinach
- 2½ cups low fat milk
- 2 thyme sprigs
- 2½ tablespoons flour
- ½ cup almond milk
- ¾ cup montery jack cheese shredded
- ½ teaspoon cayenne pepper
- ¼ teaspoon grated whole nutmeg
- 5 lasagna noodles cooked
- ¼ cup Monterey jack cheese for topping
Instructions
- Preheat oven to 425.
- Combine squash, ½ tablespoon oil, sage, garlic, ½ teaspoon salt, and black pepper in a large bowl; toss to coat.
- Arrange squash mixture on a baking sheet coated with cooking spray. Bake for 30 minutes or until squash is tender.
- Heat remaining oil in a large Dutch oven over medium-high heat. Add onion, and sauté for 4 minutes. Reduce heat to medium-low; continue cooking for 20 minutes or until golden brown, stirring frequently. Place onion in a bowl.
- Steam spinach in microwave safe steamer for 3 minutes. Cool, squeeze excess liquid from spinach. Add to onions.
- Heat 2 ½ cups milk, and thyme in a medium saucepan over medium-high heat. Bring to a boil; remove from heat. Let stand for 10 minutes. Discard thyme. Return pan to medium heat.
- Combine remaining ½ cup milk and flour in a small bowl. Add to pan, stirring with a whisk until blended. Bring to a boil; reduce heat, and simmer for 5 minutes or until thickened, stirring constantly. Remove from heat; stir in teaspoon salt, cheese, cayenne, and nutmeg.
- Spread ½ cup milk mixture in bottom of a 8 x 8-inch glass or ceramic baking dish coated with cooking spray. Arrange noodles to fit over milk mixture; top with half of squash mixture, half of spinach mixture, and ¾ cup milk mixture. Repeat layers. Spread remaining milk mixture over noodles. Top with ½ cup cheese.
- Bake for 30 minutes, and remove from oven. Let lasagna sit 10 minutes prior to serving.
Shelby Law Ruttan says
This is my favorite fall lasagna recipe, the nutmeg flavored béchamel, roasted squash and caramelized onions combined give this lasagna a hearty comforting flavor.
Diane says
Why use Almond milk if you are going to use dairy cheese?
Shelby Law Ruttan says
Hi Diane, I use almond milk because I don't drink or like regular milk (pretty sad because I grew up on a farm!). It had nothing to do with the fact that it was dairy. You can use regular milk in this recipe if you wish. It won't affect the outcome. Thanks for stopping by!
Jersey Girl Cooks says
I love your version of lasagna. I get tired of eating the same meat kind. i like how you used almond milk too.