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.
How much garlic powder do you use? The recipe doesn’t include it in the ingredients.
Hi Diane! So sorry for any confusion. The recipe has been updated with the amount of garlic powder you need 🙂 Thanks for asking!
Can you do this in the air fryer
You might be able to, but I have not personally tried it yet, Karen! Would love to know if you do and what you think!
Love this recipe idea. With it being almost time to plant our garden, this will be perfect for the PLETHORA of zucchini we’ll have!
It is the perfect thing to do with SO much squash and zucchini! Can’t wait to hear what you think, Margaret!
Hi London , this recipe sounds delish , was wondering why the sodium content was so high in this recipe… Is there a way to cut back on the sodium, I’ll still make it & let everyone salt their own ….Thanks for the recipe !!
Hi Judy! Parmesan cheese, breadcrumbs, and the added salt contribute to the somewhat high sodium count. You can definitely decrease the amount of salt added as well as look for a breadcrumb mixture that does not have as much sodium to help decrease it a bit. Would love to hear how it turns out for you!
This recipe is actually on the menu for me this week along with some salmon! Can’t wait to give it a go!
Yay!! Can’t wait to hear what you think, Jules!!
This was a big hit at our Christmas Eve dinner! Thanks so much for the recipe!
Yay!! So so happy you and the family enjoyed it, Donna!
Very good! We’ll make it again 🙂
Yay!! So happy you enjoyed it. Thanks for the comment and rating 🙂
Great flavor, too watery. I made it again but salted the squash slices, let them sit 5 minutes and squeezed them in paper towel. The end result was less watery and more like a casserole.
That’s a great idea to dry them out a bit beforehand. I’ll have to try that next time! Thanks so much for your feedback, Joyce!
I found that baking it for a shorter period of time (20 minutes) at a higher temp (400) and leaving it uncovered the entire time, resulted in a firmer squash with less water in the bottom of the pan. I also found that leaving a space around the edge of the pan caused the small amount of liquid that did form, to evaporate.
Loved this! Thanks for the great recipe!
You’re so welcome, Mollie! So happy you enjoyed it 🙂
Loved this! The second time I made this I forgot the Parmesan cheese. Ugh. However I subbed with mozzarella and Italian breadcrumbs. Almost tasted like pizza…tried it a third time with tomato sauce. It was yum.
Thanks so much for the recipe! My entire family loves it.
Hi Lillian! I absolutely love your idea to add tomato sauce… I bet that was delicious! Thanks so much for the comment 🙂
This looks absolutely delicious! I have to make this ahead of time and I was just wondering if I could go ahead and sprinkle the breadcrumbs and parmesan mixture over the zuchinni and squash and put it in the fridge or should I wait and sprinkle it after I take it out of the fridge and bring it room temperature? Thank you so much! 🙂
Hi Savannah! Yes! You can go ahead and sprinkle the breadcrumbs/parmesan on top of the squash and refrigerate it. Bring the entire casserole to room temp before you bake it for the best results! Hope this helps 🙂