Why you’ll love this family favorite recipe!

Zucchini and yellow squash are some of the overlooked vegetables that somehow magically reappear during the summer months and at a Thanksgiving dinner table.
I first discovered my love of cooking with this delightful combo when I ended up with enormous bags full of fresh summer produce from a friend.
After making a few batches of this Sautéed Zucchini and Squash, I started to run out of recipe ideas.
It would have been a sin to let all those veggies go bad, so I had to brainstorm a new summer recipe.
Summer squash casserole has always been one of my favorite summertime side dishes. But, it’s usually full of ingredients like sour cream and Ritz crackers. (I love those buttery crackers, but there’s a time and a place for them.)
This time, I channeled that bounty of produce into a healthier version of the traditional casserole. I decided to transform it into something simple to make, baked in the oven, and a sure-fire family favorite.
And the results were a crispy, flavorful, and easy side dish that held its own against the original recipe. Once you make this classic Southern recipe with fresh yellow squash and zucchini, you’ll wonder where it’s been your whole life.
Excellent! I will definitely make this again.
– Collette


Ingredients and Substitutions
For the exact measurements and detailed instructions, please see the recipe card below.

- Parsley. Not absolutely necessary but it makes the casserole really pretty when serving. You can also use fresh thyme or other herbs you love.
- Squash. Feel free to use all yellow summer squash or all zucchini if that’s what you have. However, the alternating colors are what make this casserole so unique and pretty!
- Olive oil. You can also use any other type of oil that does not have a ton of flavor. Avocado, safflower, and sunflower oils will all work equally as well.
- Garlic Powder. You only need a little bit, but it’s the secret ingredient that gives this dish a unique flavor!
- Parmesan cheese. Regular, dairy-filled Parmesan cheese is best. You can also use vegan and dairy-free Parmesan cheese. If necessary, you can sub in another variety, like sharp cheddar cheese, but the result won’t be quite the same.
- Panko Breadcrumbs. You can use regular breadcrumbs or gluten-free breadcrumbs. The taste will be minimally affected. You can substitute with a seasoned breadcrumb mixture, but you will need to make sure to adjust the amount of salt you add
Step-by-step Instructions
Please see the recipe card below for the full instructions, ingredient amounts, and a printable recipe.
Prep the squash.
Slice the squash into ¼-inch rounds using a mandolin or sharp knife. Thicker slices will need more time; thinner ones can turn soggy.
Sprinkle with salt and let sit for 10 minutes, then pat dry. This draws out excess moisture so the casserole bakes up crisp instead of watery.


Layer in the pan.
Layer the zucchini and yellow squash, alternating types, in a 9-inch square baking dish.


Season the casserole.
Lightly season the layered squash with salt and pepper.
Whisk together breadcrumbs, Parmesan cheese, and garlic powder. Then, pour the mixture in an even layer over the zucchini and squash.

Bake in the oven.
Cover the baking dish with aluminum foil and bake in preheated 350°F oven for 30 minutes. It may take a few minutes more if the slices were cut thick, or less time if the squash slices are thin.
Broil for 3-5 minutes. Keep a close eye on it! The topping will crisp up and turn golden brown quickly.

FAQs
Yes, you can definitely freeze squash casserole. However, be sure to let it cool completely. Then, cover the pan in plastic wrap so little to no air is coming into contact with the casserole. It should keep in the freezer for up to 2 to 3 months.
Yes, it is easy to prep summer squash casserole ahead of time. Follow all directions but wait to bake until you’re ready to serve. Cover tightly with foil or prepare in an airtight container and refrigerate for up to 2 days. Bring to room temperature and bake according to directions.
The answer to keeping your casserole from getting watery is to salt before cooking. Squash releases extra moisture while cooking. However, there is a trick to prevent this. After you’ve sliced your squash, sprinkle it with salt, let it sit for about 10 minutes, then blot dry the moisture that the salt drew out.
What to Serve with Squash Casserole?
This dish is an excellent side for family meals. Try one of these recipes alongside it.
For some flavor, try out this Hot Honey Chicken. Or get fancy with Chicken Cordon Bleu.
Skip the potatoes and try this zucchini casserole with Air Fryer Steak or Filet Mignon.
If you’re a seafood lover, go for Panko Crusted Salmon, Lemon Garlic Baked Salmon or Air Fryer Salmon.
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Zucchini & Squash Casserole

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Ingredients
- 2 lbs. summer squash zucchini and yellow squash, cut into ¼-inch slices
- 2 ½ tablespoons. olive oil
- 1 ¼ teaspoons salt divided
- ½ teaspoon pepper
- ⅓ cup grated Parmesan cheese grated
- ⅓ cup Panko breadcrumbs gluten-free
- ¼ teaspoon garlic powder
- 2 tablespoons fresh parsley finely chopped
Instructions
- Preheat oven to 350 degrees.
- Cut yellow squash and zucchini into thin, ¼-inch slices.2 lbs. summer squash
- Sprinkle ½ teaspoon salt over the zucchini and squash slices. Let sit for 10 minutes and then dab to remove excess moisture with a paper towel.
- Spray a 9-inch square baking dish with non-stick cooking spray.
- Alternatively, overlap the zucchini and squash in a row. (See pictures.) You should be able to form 4 rows.**
- Drizzle olive oil over the zucchini and squash and then sprinkle with salt and pepper.2 ½ tablespoons. olive oil, ½ teaspoon pepper
- In a small bowl combine Parmesan cheese, breadcrumbs, and garlic powder. Toss to combine and then sprinkle over the zucchini and squash.⅓ cup grated Parmesan cheese, ⅓ cup Panko breadcrumbs, ¼ teaspoon garlic powder
- Cover baking dish with aluminum foil and bake in preheated oven for 30 minutes.
- Remove foil and turn heat to a High broil. Broil for an additional 5-7 minutes, or until breadcrumb topping starts to turn a golden brown.
- Serve immediately with fresh parsley and enjoy!2 tablespoons fresh parsley
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Video
Notes
- Cheese: Can use a vegan Parmesan cheese substitute.
- Squash: I like to get small-medium, similarly-sized summer squash so they will be able to fit into four rows easily!
- Tools: A mandolin gives you the most precise slices so they all cook at a similar rate.
- Salt: A little salt will help prevent a soggy mess. Let the salted squash sit, then blot dry. The salt draws out excess moisture.
- Breadcrumbs: Try out Italian breadcrumbs. Since they’re pre-seasoned and often contain salt, you will have to adjust the other seasoning ingredients.
- Broiling: This gives it a great crunchy topping.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Other Squash Recipes
If you like the best yellow squash casserole, make sure to check out these other easy recipes.












This was a fantastic easy & healthy recipe.
Yay! So happy to hear you enjoyed the recipe, Janelle. Thanks so much for your comment and rating 🙂
This looks delicious, thank you for sharing!
You’re so welcome, Suzzanne!
Absolutely delicious- I added in a little shredded Gouda cheese- super easy and delicious
Yay! So happy you enjoyed the recipe, Kelli. The Gouda sounds amazing!!
I, have been making this recipe for a long time with great success. I, put a light layer of minuet rice to soak up some of the water and added a small can of tomato paste before layering my vegetables. After cooking this recipe and having a little leftover zucchini, I, made a few zucchini boats and chopped up the remaining casserole to fill the boats with the mixture topped with shredded cheese. Yum Yum.
Wow! What a great idea. The tomato and rice sounds like delicious additions. So happy you’re enjoying the recipe, Edward!
The recipe is very interesting, I have to try it
Yay! Excited to hear what you think 🙂
Thank you for this excellent and healthy recipe
You’re so welcome! Thanks for your comment 🙂
So good! I have a garden and a plethora of summer squash coming out of it. Always looking for new recipes to try and this was a fantastic healthy one that was tasty!
Yay, Carolanne! So happy to hear you enjoyed the casserole recipe. Fresh garden squash are the best to use, too! Thanks so much for your comment and rating 🙂
I have an old Gourmet Magazine recipe just like this. I think that one didn’t have breadcrumbs but it had basil leaves scattered between the vegetables. Every time I made it, I would get ohs and ahs for this simple recipe that I made in a pie dish. Thanks for reminding me of it!
You’re so welcome, Alene! What a great idea to add fresh basil – we have some in our garden so I’ll have to try that out this summer! Thanks for your comment!
This was delicious. I added mushrooms and used almond flour as we are paleo. Key is to broil at the end so it is browned and crispy. So yummy and light but has that comfort casserole feeling. Will be making again and again.
What a great idea to add some mushrooms, Paula! So happy you enjoyed the recipe. Thanks for the comment! 🙂
This might be a silly question. Can I use the dry parm that goes on top of pasta? Or does it have to be the packaged kind in the refrigerated section?
Yes! You absolutely can use the dry parmesan cheese. Hope you enjoy the recipe 🙂