Oh, it’s time for butternut everything! And this creamy vegan Butternut Squash Lasagna is definitely a big part of everything. Roasted butternut squash is mashed and layered between lasagna noodles with sage-kissed caramelized onions and creamy cashew mozzarella. It’s baked until golden at the edges, then finished with toasted walnuts. It’s my fall lasagna to bring to potlucks, serve at holidays or enjoy for Sunday night supper.
The idea for butternut squash lasagna came from a butternut ravioli I used to eat all the time at a restaurant I worked at lifetimes ago. I will always love squash with sage and something creamy, but standing at a floured counter folding dozens of little ravioli is a project I will save for very special occasions. Put it all in a 9×13 and everybody wins.
How This Vegan Butternut Squash Lasagna Comes Together
The oven is going to work hard, but you are going to remain cool, calm and collected as always. First, the squash roasts until completely soft, concentrating all that flavor. Then you mash it with lemon juice, nutmeg, cinnamon and Aleppo pepper for a little fruity spice. Meanwhile, the onions cook down slowly with rubbed sage until they’re soft, golden and caramelly. The mozzarella is my pourable cashew and silken tofu concoction that gets browned on top and stretchy inside, and you’ll blend that up in just a few minutes.
Once all the parts are ready, layer everything up and bake. When the top is deliciously golden, scatter on the toasted walnuts and a little parsley for a pop of green. Stunning!
A quick note on timing before you start: the squash and onions take the longest, so get those going first. While they cook, bring a large pot of salted water to a boil and blend the mozzarella. Cook the pasta according to package instructions until just al dente. Depending on the brand and width of your noodles, you might want a little insurance, so boil 16 just in case.
Why No Vegan Ricotta?
As we all know, most lasagnas have a ricotta layer, but between the squash, onions and mozzarella, I didn’t think this one needed another thing in there.
That said, if you love ricotta, add a few dollops of my Whipped Tofu Cashew Ricotta throughout the filling. Sage, squash and ricotta are obviously very happy together. I just wanted to keep it simple. But go for it if you’re feeling extra. You can also use storebought, but that gets expensive.
About The Liquid Mozzarella
This is the creamy deliciousness that holds it all together. Raw cashews, silken tofu, nutritional yeast, lemon juice, apple cider vinegar and a splash of sauerkraut juice get blended completely smooth with tapioca starch, so before baking it pours like cream.
The tapioca is part of what makes the magic happen. In the oven, the mozzarella sets and browns in spots while getting a little stretchy between the layers.
On the top layer, pour it all the way to the edges so you get mozzarella over the whole surface. It tends to pool in the middle, so if it doesn’t spread out on its own, use a spatula to push it into the corners. If some of it sneaks down the sides into the lasagna, good. It gets browned and yummy.
I strongly recommend using the sauerkraut juice if you have it. It gives the mozzarella a little fermented tang without making your lasagna taste like sauerkraut. But if your jar doesn’t have enough brine to spare, use a little extra lemon juice and apple cider vinegar instead.
Roasting The Butternut Squash (You Can Buy Precut, Too!)
Roasting is what makes the butternut squash so good here. It gets soft and sweet, with those browned caramelized edges that give the lasagna so much more flavor. So don’t boil or steam it. Both add water, and there is already plenty happening in a lasagna without watery squash getting involved.
If you’re starting with a large butternut, no need to peel! Slice it in half lengthwise, scrape out the seeds and place it flesh side down on a large baking sheet lined with parchment paper. Roast until a fork goes through the skin with no resistance. Then just scoop the flesh out.
But precut squash is perfectly fine! Toss the cubes with olive oil and roast on a sheet pan until tender and browned in spots.
Either way, you want about 6 cups of cooked squash. Slightly under is fine. Anything over is a cook’s snack.
How To Layer It
Three layers of noodles, with the squash and onions divided between the first two.
First layer: A layer of noodles, four across, in your oiled 9×13 dish. Half the mashed squash, half the caramelized onions and 3/4 cup of mozzarella drizzled over the top.
Second layer: Four more noodles, the rest of the squash, the rest of the onions and another 3/4 cup of mozzarella.
Top layer: The final four noodles, then all the remaining mozzarella poured over the top and spread to the edges.
Once it’s baked and rested, scatter a handful of toasted chopped walnuts over the top. I love the crunch against all those soft layers, and that slightly bitter, nutty flavor is so good with the sweet squash and caramelized onions. Plus, look how pretty!
Tips for The Best Vegan Butternut Squash Lasagna
Make ahead: Caramelize the onions a day or two ahead and refrigerate them. You can also roast and mash the squash ahead, which makes assembly much faster.
Taste the squash: Before you start layering, grab a spoon and taste the mashed squash. Every butternut is a little different, some sweeter and some blander, so this is your chance to add another pinch of salt or a squeeze of lemon.
Spare noodles: This is why you boil 16. If a noodle tears, use it in the middle layer and patch it with a piece of a spare, and nobody will ever know. Save your prettiest four for the top.
Let it rest: I know it smells amazing, but give it the full 25 minutes. The mozzarella firms up as it cools, so the slices hold together and you can see all the layers when you lift one out.
Toast the walnuts: Toast them in a dry pan over medium heat for 5 minutes or so, stirring often, until they smell toasty and get a little darker. Or put them on a small baking sheet and slide them into the oven for 8 to 10 minutes while the lasagna bakes. Chop them once they’ve cooled.
Butternut Squash Lasagna FAQ
Can I use canned or frozen butternut squash? Frozen cubes are fine, but you will need a lot so it will probably get expensive. Roast them straight from frozen on a hot sheet pan until tender and browned around the edges. I wouldn’t use canned puree here. It’s much wetter and you miss out on all that roasted squash flavor.
Do I need a high-speed blender for the mozzarella? Nope. If your blender is high speed (like Vitamix), you can toss the cashews in as is. If it’s more of a, uh, workhorse, soak them first, anywhere from a couple of hours to overnight, so they blend completely smooth. You can also boil them for 20 minutes or so to get them soft. Either way, drain them and let them cool before blending.
Does it freeze well? For sure. I prefer freezing it after baking. Cool completely, slice into portions and freeze in an airtight container for up to 2 months. Reheat at 350°F until hot all the way through.
Can I make it gluten-free? Easily. Use your favorite sturdy gluten-free lasagna noodles. Brown rice blends tend to hold up nicely. Everything else is already gluten-free.
Other Lasagna Recipes To Try
Butternut Squash Lasagna With Caramelized Onions
Notes
Ingredients
For the butternut squash
- About 5 1/2 pounds whole butternut squash or 4 1/2 pounds peeled, seeded, precut butternut squash
- 1 1/2 tablespoons olive oil if using precut squash to roast
- 2 tablespoons refined coconut oil for the mixture
- 2 tablespoons fresh lemon juice
- 1 teaspoon salt
- 1/2 teaspoon ground nutmeg
- 1/2 teaspoon Aleppo pepper
- 1/2 teaspoon ground cinnamon
For the caramelized onions
- 3 tablespoons olive oil
- 3 large yellow onions thinly sliced
- 3/4 teaspoon salt
- 1 1/2 teaspoons dried rubbed sage
For the liquid mozzarella
- 1 1/2 cups raw unroasted cashews
- 2 tablespoons fresh lemon juice
- 2 tablespoons sauerkraut juice (see note)
- 2 tablespoons apple cider vinegar
- 2 tablespoons olive oil
- 2 tablespoons nutritional yeast
- 1 1/2 teaspoons salt
- 16 ounces silken tofu drained
- 1/4 cup tapioca starch
For the lasagna
- 12 to 16 lasagna noodles
- Olive oil for the pan
For finishing
- 1/2 cup walnuts toasted and roughly chopped
- A few tablespoons chopped fresh parsley
- Aleppo pepper for sprinkling
Instructions
Roast the squash:
- Preheat the oven to 425°F.
- For whole squash: Cut the squash in half lengthwise and scoop out the seeds. Place cut side down on parchment-lined rimmed baking sheets. Roast for 45 to 60 minutes, until very tender. Let cool enough to handle, then scoop out the flesh.
- For precut squash: Toss the cubed squash with the olive oil. Spread on parchment-lined rimmed baking sheets and roast for 30 to 40 minutes, stirring once, until very tender and browned in spots.
- Place 6 cups of the roasted squash in a mixing bowl. Add the coconut oil, lemon juice, salt, nutmeg, Aleppo pepper and cinnamon. Mash until smooth and spreadable. Set aside. A little under 6 cups is fine, and any extra is a snack.
- Reduce the oven temperature to 375°F.
Caramelize the onions:
- Heat the olive oil in a soup pot over medium heat.
- Add the onions and salt. Cook for about 10 minutes, stirring frequently, until they’ve collapsed and there’s room to work. Reduce the heat to medium-low and continue cooking for 30 to 40 minutes, stirring occasionally, until the onions are very soft and golden.
- Stir in the rubbed sage and cook for 1 minute. Remove from the heat.
Make the liquid mozzarella:
- In a high speed blender, blend the cashews, lemon juice, sauerkraut juice, apple cider vinegar, olive oil, nutritional yeast, salt, silken tofu and tapioca starch until completely smooth. Set aside.
Cook the noodles:
- Put a large pot of salted water on to boil while the squash and onions are going. Cook the lasagna noodles just until al dente, according to package directions.
- Drain and lay the noodles flat on a lightly oiled baking sheet or clean kitchen towels so they don’t stick together.
Assemble:
- Lightly oil a 9×13-inch baking dish.
- Arrange 4 lasagna noodles over the bottom.
- Spread with half of the butternut squash mixture. Scatter over half of the caramelized onions. Drizzle 3/4 cup liquid mozzarella evenly over the layer.
- Add another 4 noodles.
- Repeat with the remaining butternut squash and caramelized onions. Drizzle with another 3/4 cup liquid mozzarella.
- Top with the final 4 noodles.
- Pour the remaining liquid mozzarella over the top, all the way to the edges so the whole top browns. It tends to pool in the center, so if it doesn’t spread out on its own, use a spatula to push it into the corners. It’s ok if some sneaks down the sides.
- Bake uncovered for 35 to 40 minutes, until the lasagna is bubbling around the edges and the liquid mozzarella is set and lightly browned in spots. Rotate the dish once if needed for even browning. If the top is getting too dark before the center is hot, tent loosely with foil.
- Let rest for at least 25 minutes before slicing.
- Before serving, scatter lightly with toasted walnuts, parsley and a pinch of Aleppo pepper.
This turned out really well. I appreciated the thoughts about the ricotta and went back and forth before I decided to make the Whipped tofu cashew ricotta as well. When assembling I wondered if maybe it was the wrong call, but now I could go either way. I actually really like having it in there, but wouldn’t hesitate to try it without.
The liquid mozzarella has a great flavor and I would never have thought about bringing ACV into a cheese sub and it was amazing. I didn’t have sauerkraut juice and so I had to do the modification. The liquid mozzarella is a standout part of this dish.
The waiting once it was out of the oven was so hard.
Thank you for the feedback!