Made with fresh yellow squash, zucchini, an easy cream sauce, and plenty of cheese, this Zucchini and Squash Casserole is a comforting side dish that tastes just like dinner at Grandma’s. Creamy, cheesy, easy to make, and always a hit with the whole family!

My Kids Devour This Squash and Zucchini Casserole!

We all know that some kids will happily munch on just about any vegetable, while others can be a little more hesitant when it comes to anything green… or squash-like. Can I get a witness?

But this delicious squash and zucchini casserole might just win them over! It’s layered with melted cheese, a creamy sauce, tender zucchini and yellow squash, and a crispy Panko topping. Even picky eaters will have a hard time saying no!

Recipe Ingredients

• Fresh Zucchini and Yellow Squash: Slice into ½-inch-thick rounds, or spiralize if you prefer.
• Butter: Use 1 stick of unsalted butter, softened to room temperature.
• Flour: All-purpose flour thickens the creamy sauce.
• Milk: I use regular milk, but lower-fat milk works, too.
• Italian seasoning: Use your favorite Italian seasoning blend, or swap in another herb and spice blend you love.
• Fresh Garlic: Mince or press the garlic before adding it to the sauce.
• Olive Oil: For sautéing the zucchini and squash and drizzling over the casserole. Avocado oil or another neutral cooking oil will also work.
• Salt and Pepper: Season to taste.
• Mozzarella and Parmesan: I use shredded mozzarella and grated Parmesan for the cheesy layers, but you can swap in your favorite shredded cheese.
• Panko: Regular or gluten-free Panko breadcrumbs will work.

How to Make Zucchini and Squash Casserole

1. Prep: Preheat the oven to 375˚F. Grease a 9×13-inch baking dish with butter and set aside. Cut the zucchini and yellow squash into ½-inch thick slices. Place the sliced vegetables in a colander, sprinkle with salt, and let them stand to drain.
2. Make the cream sauce: Melt the butter in a saucepan over medium heat. Whisk in the flour and cook for 2 minutes, whisking constantly. Slowly add the milk and Italian seasoning, whisking constantly until smooth. Simmer for 8 to 10 minutes until the sauce thickens.
3. Dry and season the vegetables: Use paper towels to pat the zucchini and squash completely dry. Transfer them to a large bowl and toss with the garlic, a drizzle of olive oil, and a little salt and pepper.
4. Sauté the veggies: Heat the remaining tablespoon of olive oil in a large skillet over medium-high heat. Add the vegetables and cook for about 3 minutes, stirring frequently, until they just begin to soften. Remove from the heat, drain any excess juices, and set aside.
5. Layer the casserole: Spoon ¾ cup of the cream sauce over the bottom of the prepared baking dish. Arrange half of the sautéed zucchini and squash over the sauce, then sprinkle with 1 cup of mozzarella and ⅓ cup of Parmesan. Repeat the layers with the remaining vegetables, mozzarella, and Parmesan. Sprinkle the Panko over the top and drizzle with a little olive oil.
6. Bake: Bake for 30 to 35 minutes, or until the top is golden brown and the casserole is bubbling around the edges. Remove from the oven and let cool for 10 minutes before serving with a garnish of fresh parsley and grated Parmesan.

Easy Variations

• Try different seasonings: Swap the Italian seasoning for Cajun seasoning for a little kick, or try lemon pepper, seafood seasoning, herbes de Provence, or your favorite garlic and herb blend.
• Vegetable options: Use this same basic recipe to make a broccoli and cauliflower casserole. Simply replace the squash with lightly steamed broccoli and cauliflower.
• Make it a main dish: Enjoy this zucchini casserole as a vegetarian dinner, or make it heartier by adding layers of cooked Italian sausage, chicken, or diced ham.

What To Serve with Zucchini Squash Casserole

• Seafood: Pair it with Old Bay roasted salmon for an easy dinner. The bold seasoning is great with the creamy, cheesy casserole.
• Chicken: These pan-seared Cajun butter chicken thighs are juicy, flavorful, and go with just about anything.
• Dessert: Finish dinner with Southern banana pudding, made with layers of creamy vanilla pudding, bananas, and fluffy meringue.

How to Store and Reheat Leftovers

• Refrigerate: Cover the leftovers tightly or transfer them to an airtight container and refrigerate for up to 4 days.
• Freeze: Transfer the cooled casserole to freezer-safe containers or freezer bags, removing as much air as possible before sealing. Freeze for up to 2 months for the best quality.
• Reheat: Place the desired portion in an oven-safe dish and bake at 350˚F until heated through. Frozen leftovers will take longer to reheat, so make sure the casserole is hot all the way through before serving.

More Zucchini Recipes

• Zucchini Fritters
• Zucchini Tomato Gratin
• Zucchini Lasagna with Ground Beef
• Parmesan Zucchini Fries