Cheesy Zucchini and Squash Casserole
Dec 01, 2020, Updated Sep 04, 2021
This post may contain affiliate links. Please read our disclosure policy.
Using fresh yellow squash, colorful zucchini, an easy cream sauce, and plenty of cheese, this Cheesy Zucchini and Squash Casserole feeds a houseful and tastes just like dinner at Grandma’s. The whole family will love it!
![overhead picture of squash and zucchini casserole in baking dish](https://easyweeknightrecipes.com/wp-content/uploads/2020/11/Yellow-Squash-and-Zucchini-Noodles-Casserole-8.jpg)
My Kids Devour this Easy Squash Casserole!
So we all know that, while some kiddos will happily munch raw or cooked veggies of all kinds… many will be a bit leery (or downright rebellious) of anything, you know… green. Or squash-like. Can I get a witness?
But, this delicious squash casserole beats the odds! Even picky eaters will love the layers of melted cheese, creamy sauce, tender rounds of zucchini and yellow squash, and crunchy panko topping!
Recipe Ingredients
- Fresh Zucchini and Squash: Cut these into ½-inch thick slices, or spiralize them if you prefer.
- Butter: You’ll need one stick of unsalted butter at room temperature.
- Flour: You’ll need ½ a cup of all-purpose flour for the cream sauce.
- Milk: I use regular milk, but you can definitely substitute lower fat milk.
- Seasoning Blend: I use 2 teaspoons of an Italian seasoning blend.
- Fresh Garlic: Mince or press the garlic.
- Olive Oil: For sautéing the squash and zucchini, plus more for drizzling.
- Salt and Pepper: Season to taste.
- Mozzarella and Parmesan: You’ll need 3 cups of mozzarella cheese and 1 cup of parmesan cheese for layering in the casserole.
- Panko: Regular Panko or gluten-free will work.
- Chopped Fresh Parsley and Grated Parmesan: For the garnish.
How to Make Cheesy Zucchini and Squash Casserole
- Prep the Oven, Baking Dish, and Veggies. Preheat the oven to 375˚F. Grease a 9×13 baking dish with butter and set aside. Cut or spiralize the zucchini and yellow squash; place in a colander, sprinkle with salt and let stand to drain.
- Make the Cream Sauce. Melt the butter in a saucepan over medium heat. Whisk in the flour; continue to whisk and cook for 2 minutes. Slowly add in the milk and Italian seasoning, whisking constantly until smooth. Simmer the sauce for 8 to 10 more minutes, whisking frequently until it thickens.
- Dry and Season the Drained Veggies. In the meantime, use paper towels to pat dry the squash and zucchini as much as you can, and then place it in a large bowl. Add the garlic, a drizzle of olive oil, and a little bit of salt and pepper; toss to combine.
- Sauté the Veggies. Heat the remaining tablespoon of olive oil in a large skillet over medium-high heat. Add the squash mixture to the hot oil and cook for 3 minutes, or until it just starts to soften, while stirring frequently. Remove from the heat, drain any juices, and set the sautéed veggies aside.
- Layer the Casserole. Spoon ¾-cup of the cream sauce over the bottom of the buttered baking dish. Arrange ½ of the squash mixture over the cream sauce, then sprinkle with 1 cup of the mozzarella cheese and ⅓ cup of the parmesan cheese; repeat the layers a second time. Finally, sprinkle panko crumbs over the top and drizzle with olive oil.
- Bake. Bake the assembled casserole for 30 to 35 minutes, or until the top is golden brown. Remove from the oven and let it cool for 10 minutes. Garnish with parsley and parmesan cheese and serve.
- Enjoy!
Tips for Success
- Don’t Overcook the Squash: Be sure to sauté the squash and zucchini only until it begins to soften because it will still have to bake. Overcooking in the sauté stage will create a mushier texture in the finished dish.
- Adjust Seasonings Frequently: Since this dish contains seasoned vegetables, a cream sauce, and two kinds of cheese, be careful about over-seasoning and under-seasoning. Taste the sauce and veggies at least twice to make sure that all the components taste right individually. Doing this helps make sure your finished casserole is correctly seasoned.
- Choose One: If you don’t have both yellow squash and zucchini available, feel free just to use one or the other!
Variation Ideas!
- Cajun Spice: Try substituting a Cajun seasoning blend for the Italian blend, but be careful to use less salt if your blend already includes salt. (Also, be aware that Cajun blends can be quite spicy; you may wish to add less than the two teaspoons called for in the original recipe.)
- Veggie Ideas: You can also use this basic recipe and technique to create a broccoli and cauliflower casserole! Substitute very lightly steamed broccoli and cauliflower for the squash and zucchini.
- Main-Dish Magic: Want to make this a main dish? Try adding layers of cooked Italian sausage, cooked chicken, or diced ham to the casserole. So tasty!
What Goes with Zucchini and Squash Casserole?
- Salmon: Try this casserole as a side to accompany a beautiful entree of Old Bay Roasted Salmon. The salmon’s classic seasoning will pair perfectly with the cheesy vegetables!
- Chicken: These Pan-Seared Cajun Butter Chicken Thighs are an easy recipe that goes with just about anything, especially a creamy, garlicky side like Cheesy Squash Casserole!
- Banana Pudding: Thanks to its light, vanilla-accented flavor profile and foamy meringue topping, this tasty traditional Southern Banana Pudding is a fantastic follow-up to squash casserole.
How to Store and Reheat Leftovers
- To refrigerate. Cover leftovers tightly in an airtight container and store in the refrigerator for up to 4 days.
- To freeze. Place in freezer bags or other freezer-safe containers, leaving as little air in the container as possible before sealing.
- To reheat. Place the desired portion of casserole in an ovenproof dish. Bake at 350˚F until heated through. Reheating will take longer for frozen leftovers, so check carefully before eating.
Cheesy Zucchini and Squash Casserole
Ingredients
- 2 large zucchini,, cut into ½-inch thick slices OR spiralized
- 2 large yellow squash,, cut into ½-inch thick slices OR spiralized
- 1 stick (8 tablespoons) unsalted butter,, at room temperature
- ½ cup all-purpose flour
- 3 ½ cups milk
- 2 teaspoons Italian Seasoning
- 4 cloves garlic,, minced
- 1 ½ tablespoons olive oil,, divided
- Salt and freshly ground pepper,, to taste
- 3 cups shredded mozzarella cheese,, divided
- 1 cup grated parmesan cheese,, divided
- 1 cup panko crumbs
- Olive oil,, for drizzling
- Chopped fresh parsley,, for garnish
- Grated parmesan cheese,, for garnish, optional
Instructions
- Preheat oven to 375˚F.
- Grease a 9×13 baking dish with a bit of butter and set aside.
- Cut or spiralize the zucchini and yellow squash; place in a colander, sprinkle with salt, and let drain.
- In the meantime, melt the butter in a 2-qt. saucepan set over medium heat.
- Whisk in the flour; continue to whisk and cook for 2 minutes.
- Slowly add in the milk, stir in Italian seasoning, and continue whisking constantly until smooth.
- Simmer and whisk frequently for 8 to 10 minutes, or until sauce thickens.
- Meanwhile, using paper towels, pat dry the squash and zucchini as much as you can and then place in a large bowl. Add garlic.
- Add 1/2 tablespoon olive oil to the vegetables and season with salt and pepper to taste; toss to combine.
- Heat remaining 1 tablespoon olive oil in a large skillet set over medium-high heat.
- Add squash and zucchini to the hot oil and cook for 3 minutes, or until it just starts to soften; stir frequently. Remove from heat, drain, and set aside.
- Spoon ¾-cup of the prepared cream sauce over the bottom of the buttered baking dish.
- Arrange ½ of the squash mixture over the cream sauce.
- Sprinkle with 1 cup of the mozzarella cheese and ⅓ cup of the parmesan cheese.
- Add the rest of the squash mixture and cover with the rest of the cream sauce, then sprinkle with remaining cheeses.
- Sprinkle panko crumbs over the top and drizzle with olive oil.
- Bake for 30 to 35 minutes, or until top is golden.
- Remove from oven and let cool 10 minutes.
- Garnish with parsley and parmesan cheese. Serve.
Equipment
- Stove
- Oven
Nutrition
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.
Great recipe! For those saying prep took to long… get a mandolin! You will zip through the zucchini and squash in minutes! I sliced mine right into a frying Pan, salted and allowed it to sit.. added the garlic and olive oil and sautéed.. placed in colander to drain while I made the sauce which was quick and easy as well! Having the right tools always speeds up the process! I am about to bake mine now and can’t wait to try it!
I am very glad you enjoyed it! Thank YOU! 🙂
How much milk?
Hi!
It’s 3½ cups milk. All that information is in the recipe card located towards the bottom of the post and right above the “comments” section.
I used 2 larger zucchini and what summer squash I had and used a mandolin per other’s suggestions. I already had shredded some mozzarella so it all came together pretty quickly. I also had some “pizza” seasonings on hand and added those in with the Italian seasonings. It seemed a bit bland to me – it was like a white sauce vegetable lasagna minus the noodles and it was close to being really good but just fell a little flat. Perhaps it’s the not knowing how many cups of squash is needed, or exactly what the proper amount of salt/pepper should be (I thought I salted the heck out of the squash before letting it drain in the colander so was afraid to add more while cooking and really don’t want to taste-test partially cooked squash for verification of the level of salt that is appropriate), but it lacked something. I may make this again but would have to season it quite a bit more.
This was a hit for my family for supper my husband hates casserole but he told me I can make this one again lol!! I added onion and ham to this recipe it was perfect well except some of the veggies were not all the way done I shoulda cooked it a little more but it was awesome otherwise!!!
That’s great to hear! I am very glad everyone enjoyed it! Thank you for chiming in! 🙂
Okay, so I got nervous because I realized mid-recipe that I had cut up a BUTTERNUT squash and not a summer squash (rookie mistake) BUT I made the recipe anyway, added some diced onions, went light on the parmesan cheese and used Italian bread crumbs with melted butter mixed in for the topping and let me tell you… I brought this dish to a party and EVERYONE loved it, including my sister who said she was “zucchinied out.” In other words, was a hit. So if you’re looking for alterations, give this a shot!! I liked it too. 🙂 Sweet and savory as well as creamy!
That’s great! I am very happy everyone enjoyed it! Thank YOU! 🙂
Very tasty side dish. I sautéed some baby portabella mushrooms along with the zucchini and summer squash mixture. My husband says it tastes like green bean casserole!
I’m very glad you enjoyed it! Thank YOU! 🙂
How many servings (approximate size) does this make and what size baking dish is required?
I badly want to make this but need to scale it to 4 servings.
Hi! I am not sure what I did wrong but mine doesn’t look anything like your photo? The panko crust is thick (this part was yummy and I used the right measurements) but the photo looks like it has no panko and more like a egg breakfast casserole. My sauce kinda clumped up and resembled a sausage biscuit gravy if that makes sense and it wasn’t super thick
Before the layering? Any ideas?
can I make this a day ahead and then bake the next day?
Looking for the same answer! Did you make ahead and bake next day?
Rather a labor-intensive recipe with lack-luster results. The sauce was far too much and I used five squash and zucchini and needed to be seasoned. This could be prevented with better proportion instructions for the squash and zucchini (cups or ounces). Salting zucchini and squash also makes them turn to mush when the water is secreted so the extra cooking in a pan is unnecessary. Mozzarella is also a really wet cheese. It just didn’t work all together. The flavor was off, consistency was off and just not something I’d make again.