Homemade Yellow Squash Lasagna

Finding creative ways to use up those summer yellow squash can feel like a real puzzle, especially when your garden is producing them faster than you can keep up. And let’s be honest, there are only so many times you can sauté or grill them before your family starts giving you the side-eye at dinner.

That’s where this yellow squash lasagna comes in handy. It swaps traditional pasta noodles for thinly sliced squash, creating a lighter version of the classic comfort food that still delivers all those cheesy, saucy flavors everyone loves. Plus, it’s a sneaky way to load up on vegetables without anyone complaining.

What Kind of Summer Squash Should I Use?

Yellow summer squash and zucchini are pretty much interchangeable in this recipe, so feel free to use whichever you have on hand or can find at the store. You’ll want to look for medium-sized squash that are firm to the touch and free of soft spots or blemishes. Smaller squash tend to have fewer seeds and a sweeter flavor, while the really large ones can be watery and have tougher seeds. When you’re slicing them into lasagna “noodles,” try to keep them about 1/4 inch thick so they hold up well during baking without getting mushy.

Options for Substitutions

This recipe is pretty forgiving when it comes to swaps, so feel free to work with what you have:

• Yellow squash: Zucchini works perfectly as a swap here – they’re basically interchangeable. You can also mix both if you want some variety. Just make sure to slice them evenly (about 1/4 inch thick) and pat them dry to avoid a watery lasagna.
• Baby spinach: Regular spinach, kale, or even Swiss chard can replace baby spinach. If using regular spinach or heartier greens, chop them into smaller pieces and consider wilting them in a pan first to remove excess moisture.
• Ricotta cheese: Cottage cheese is a great substitute – just blend it until smooth for a similar texture. You could also use a mix of cream cheese and sour cream (1.5 cups cream cheese + 0.5 cups sour cream) for a richer filling.
• Mozzarella cheese: Provolone or Monterey Jack can step in for mozzarella. Just keep in mind that provolone has a sharper flavor, so adjust the amount if needed.
• Fresh basil: If you don’t have fresh basil, use 1 tablespoon of dried basil instead. Add it to the ricotta mixture and it’ll still give you that classic Italian flavor.
• Egg: The egg helps bind the ricotta mixture, but you can leave it out if needed. Your lasagna might be slightly looser, but it’ll still taste great.

Watch Out for These Mistakes While Baking

The biggest mistake people make with yellow squash lasagna is skipping the salting step, which leaves you with a watery casserole that pools liquid on your plate – those 15 minutes of letting the squash sit with salt draws out excess moisture and makes all the difference.

Cutting your squash slices too thick (anything over 1/8 inch) means they won’t cook through properly and you’ll end up with crunchy, undercooked layers instead of tender ones.

Make sure to really squeeze out that spinach after microwaving it, using a clean kitchen towel or paper towels to press out as much water as possible, since any leftover liquid will make your lasagna soggy.

Finally, don’t skip the 15-minute resting period after baking – this allows the layers to set and firm up, making it much easier to slice and serve without everything sliding apart on the plate.

What to Serve With Yellow Squash Lasagna?

Since this lasagna is already packed with veggies, I love serving it with a simple side of garlic bread or garlic knots for scooping up any extra sauce on your plate. A crisp Caesar salad or mixed green salad with a light vinaigrette is perfect alongside it, especially if you want to keep the meal feeling fresh and balanced. If you’re feeding a crowd, you could also add some Italian sausage links or meatballs on the side for anyone who wants a bit more protein. This dish is pretty filling on its own though, so honestly, a good crusty bread and a glass of wine is all you really need.

Storage Instructions

Store: Keep leftover yellow squash lasagna in an airtight container in the fridge for up to 4 days. It actually tastes even better the next day after all the flavors have had time to meld together, making it perfect for meal prep or easy weeknight dinners.

Freeze: This lasagna freezes really well for up to 3 months. You can freeze the whole pan covered tightly with plastic wrap and foil, or cut it into individual portions and wrap them separately for quick grab-and-go meals.

Reheat: Warm it up in the oven at 350°F covered with foil until heated through, about 20-25 minutes. For individual portions, the microwave works great too – just heat on medium power for 2-3 minutes. The squash might release a little extra moisture when reheating, but that’s totally normal.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 900-1050
• Protein: 80-90 g
• Fat: 40-48 g
• Carbohydrates: 60-70 g

Ingredients

For the filling:

• 2 cups whole milk ricotta
• 1/3 cup grated parmesan cheese
• 3 tbsp fresh basil, finely ribboned
• 2 tsp garlic powder
• 1/2 tsp red pepper flakes
• 1/2 tsp salt
• 1/2 tsp black pepper
• 1 large egg, room temperature
• 1 tsp fresh lemon zest

For the lasagna:

• 4 large yellow squash, sliced 1/8-inch thick
• 4 cups fresh baby spinach, wilted and squeezed dry
• 2 1/4 cups marinara sauce
• 2 cups shredded mozzarella
• 2 tsp dried parsley

Step 1: Prepare the Squash and Preheat

• 4 large yellow squash, sliced 1/8-inch thick
• 1/2 tsp salt

Slice the yellow squash into 1/8-inch thick rounds—a mandoline slicer makes this quick and uniform.

Arrange the slices between paper towels and salt them lightly, then let sit for 15 minutes.

This draws out excess moisture so your lasagna won’t be watery.

While the squash sits, preheat your oven to 375°F.

Step 2: Build the Ricotta Filling and Prepare the Spinach

• 2 cups whole milk ricotta
• 1/3 cup grated parmesan cheese
• 3 tbsp fresh basil, finely ribboned
• 2 tsp garlic powder
• 1/2 tsp red pepper flakes
• 1/2 tsp salt
• 1/2 tsp black pepper
• 1 large egg, room temperature
• 1 tsp fresh lemon zest
• 4 cups fresh baby spinach, wilted and squeezed dry

In a large bowl, combine the ricotta, parmesan, fresh basil, garlic powder, red pepper flakes, salt, black pepper, egg, and lemon zest.

Stir until smooth and well combined.

In a separate bowl or microwave-safe container, microwave the fresh spinach with a splash of water for 3 minutes until wilted, then squeeze it very dry in a clean kitchen towel to remove excess liquid—this prevents soggy lasagna.

I like to add the lemon zest to the ricotta because it brightens the savory flavors without making the dish taste acidic.

Step 3: Assemble the Lasagna

• salted yellow squash from Step 1
• ricotta filling from Step 2
• wilted spinach from Step 2
• 2 1/4 cups marinara sauce
• 2 cups shredded mozzarella

Spread a thin layer of marinara sauce (about 1/3 cup) on the bottom of a 9×13 inch baking dish.

Layer one-third of the salted squash slices, then spread half of the ricotta mixture from Step 2, followed by half of the wilted spinach from Step 2.

Drizzle with more sauce and sprinkle with one-third of the mozzarella.

Repeat with another layer of squash, remaining ricotta, remaining spinach, sauce, and another third of the mozzarella.

Finish with the final squash layer, remaining sauce, and the last of the mozzarella on top.

I find that ending with cheese helps it brown beautifully and creates a golden crust.

Step 4: Bake and Rest

• 2 tsp dried parsley

Cover the lasagna with foil and bake for 30 minutes at 375°F.

Remove the foil and bake uncovered for an additional 15-20 minutes until the top is golden brown and cheese is bubbling at the edges.

Remove from the oven and let rest for 15 minutes before serving—this allows the layers to set so each slice holds together cleanly.

Homemade Yellow Squash Lasagna

Delicious Homemade Yellow Squash Lasagna recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 35 minutes mins

Cook Time 1 hour hr 5 minutes mins

Total Time 1 hour hr 40 minutes mins

Servings: 8 servings

Calories: 975

Ingredients Method

Ingredients

  

For the filling:

• 2 cups whole milk ricotta
• 1/3 cup grated parmesan cheese
• 3 tbsp fresh basil, finely ribboned
• 2 tsp garlic powder
• 1/2 tsp red pepper flakes
• 1/2 tsp salt
• 1/2 tsp black pepper
• 1 large egg, room temperature
• 1 tsp fresh lemon zest

For the lasagna:

• 4 large yellow squash, sliced 1/8-inch thick
• 4 cups fresh baby spinach, wilted and squeezed dry
• 2 1/4 cups marinara sauce
• 2 cups shredded mozzarella
• 2 tsp dried parsley

Method

 

1. Slice the yellow squash into 1/8-inch thick rounds—a mandoline slicer makes this quick and uniform. Arrange the slices between paper towels and salt them lightly, then let sit for 15 minutes. This draws out excess moisture so your lasagna won't be watery. While the squash sits, preheat your oven to 375°F.
2. In a large bowl, combine the ricotta, parmesan, fresh basil, garlic powder, red pepper flakes, salt, black pepper, egg, and lemon zest. Stir until smooth and well combined. In a separate bowl or microwave-safe container, microwave the fresh spinach with a splash of water for 3 minutes until wilted, then squeeze it very dry in a clean kitchen towel to remove excess liquid—this prevents soggy lasagna. I like to add the lemon zest to the ricotta because it brightens the savory flavors without making the dish taste acidic.
3. Spread a thin layer of marinara sauce (about 1/3 cup) on the bottom of a 9x13 inch baking dish. Layer one-third of the salted squash slices, then spread half of the ricotta mixture from Step 2, followed by half of the wilted spinach from Step 2. Drizzle with more sauce and sprinkle with one-third of the mozzarella. Repeat with another layer of squash, remaining ricotta, remaining spinach, sauce, and another third of the mozzarella. Finish with the final squash layer, remaining sauce, and the last of the mozzarella on top. I find that ending with cheese helps it brown beautifully and creates a golden crust.
4. Cover the lasagna with foil and bake for 30 minutes at 375°F. Remove the foil and bake uncovered for an additional 15-20 minutes until the top is golden brown and cheese is bubbling at the edges. Remove from the oven and let rest for 15 minutes before serving—this allows the layers to set so each slice holds together cleanly.