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!
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!
- 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.
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!
- 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
- 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
- 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.