Name: Garlic Parmesan Zucchini Casserole
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Ingredients: 4 cups grated zucchini ((I used about 3.5 medium zucchinis)); ½ teaspoon salt; ½ cup finely minced or grated onion; 1 tablespoon minced garlic; 2 eggs; ½ cup grated Parmesan cheese, plus an additional 2 tablespoons; 1 cup shredded mozzarella cheese; ½ cup shredded cheddar cheese; ½ cup Panko breadcrumbs; 2 tablespoons melted butter

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This garlic parmesan zucchini casserole is an easy side dish that pairs beautifully with just about any family meal! The old fashioned zucchini casserole recipe features fresh, shredded summer zucchini, garlic, and onion, with three types of cheese and a buttery, Parmesan breadcrumb topping. Serve the cheesy dish with grilled chicken, oven-fried pork chops, steak or shrimp. It's versatile, and always a hit!

Cheesy zucchini casserole on a wooden table

How to Make Garlic Parmesan Zucchini Casserole | 1-Minute Video

This cheesy zucchini casserole recipe has quickly become a favorite among the boys in my house! I'm telling you: if you want to get your kids (or your husband) to eat some green vegetables, then this is the recipe for you. The zucchini is mild, it's baked with three different kinds of cheese, and it's finished with a buttery Parmesan breadcrumb topping. What's not to love?!

process shot showing how to squeeze shredded zucchini dry

Ingredients

This is a quick overview of the ingredients that you'll need for an easy zucchini casserole. As always, specific measurements and complete cooking instructions are included in the printable recipe box at the bottom of the post.

Zucchini: this freshly-grated veggie is the star of the show! You'll need a total of 4 cups grated, which is equivalent to approximately 3 ½ medium zucchinis.
Salt: enhances the flavors in the dish and helps to draw out moisture from the zucchini so that you don't end up with a watery casserole.
Onion and garlic: for more flavor.
Eggs: give the casserole structure.
Parmesan cheese, mozzarella cheese, and sharp cheddar cheese: three different types of grated cheese add a variety of flavors to the casserole.
Panko breadcrumbs and melted butter: combine the panko bread crumbs with the Parmesan and melted butter to form the crispy, golden brown topping.

Process shot showing how to make zucchini casserole

How do you keep squash casserole from getting watery?

Zucchini and other summer squash naturally holds a lot of water, so you'll probably notice that the vegetable releases a lot of water as it cooks. This can be a problem when adding squash to casseroles, bakes, and sauces, since the vegetables can water down the sauce or casserole, resulting in a bland flavor and undesirable texture.

If you sprinkle the shredded zucchini with salt and allow it to sit in a colander for about 10 minutes, the salt draws out a lot of moisture from the vegetable before you add it to the casserole.

TIP: In order to make sure that I get most of the water out of the zucchini (and avoid a watery casserole), I like to wrap the zucchini in a dish towel. Squeeze it and wring it out multiple times while it's in the towel -- you will be shocked by how much liquid comes out!

Stirring together parmesan breadcrumb topping

How to Make Zucchini Casserole

This cozy, family-friendly vegetable side dish comes together easily without any special cooking skills. Just remember to allow enough time to let the zucchini sit in the colander before squeezing it dry and adding it to the casserole.

Place zucchini in a colander, sprinkle with salt, and allow to sit for about 10 minutes (this will help draw out some of the water from the zucchini). After 10 minutes, squeeze out the moisture from the zucchini.
Combine zucchini, onion, garlic, eggs, ½ cup Parmesan cheese, mozzarella cheese, and cheddar cheese in a small, greased baking dish.
Bake uncovered in a 375°F oven for 20 minutes.
Make the topping by combining melted butter with breadcrumbs and additional Parmesan cheese.
Sprinkle the breadcrumbs over the casserole and return the dish to the oven.
Bake for about 5-10 more minutes, or until the top is golden brown and crispy.

Close up front shot of a spoon in a pan of zucchini casserole

What to Serve with Easy Zucchini Casserole

This versatile casserole pairs nicely with just about any meat, seafood, or pasta. Here are a few ideas to serve with a cheesy zucchini casserole:

Horizontal side shot of a white plate with cheesy zucchini casserole

Is this casserole gluten free?

You can easily make this zucchini casserole gluten-free by using gluten-free breadcrumbs. If you want to add a little more fiber and nutrition to the dish, use whole wheat breadcrumbs (which are not gluten-free).

Close up shot of zucchini casserole on a serving spoon

Storage

Store leftover zucchini casserole in an airtight container in the refrigerator for up to 3 days. Reheat in a 350°F oven just until warmed through.

You can freeze the leftovers; however, this is not my preference because the zucchini will hold a lot of water, negatively impacting the texture and taste when thawed.

Overhead shot of hands serving a garlic parmesan zucchini casserole from a dish

Recipe Variations

I've used three different types of cheese here: Parmesan, mozzarella, and cheddar. You can substitute with an equal amount of any of your favorite cheeses -- or stick to just mozzarella or just cheddar. Other good options include Monterey Jack, Colby, Colby Jack, Pepper Jack, Gruyere, Swiss, and Gouda cheese.
Use a combination of yellow squash and zucchini, or replace all of the zucchini with yellow squash.
To serve a larger family, double all of the ingredients and bake the casserole in a larger dish. You may need to add a few extra minutes to the total cooking time, but the rest of the instructions remain the same.

Overhead shot of a serving of zucchini casserole on a white plate with a fork

Tips for the Best Zucchini Casserole Recipe

I just use a handheld box grater to shred my zucchini, but you can also put it through a food processor if you prefer.
Make sure that you drain the zucchini before adding it to your casserole. To do so, sprinkle it with salt, let it sit in a colander for about 10 minutes, and then wring it out in a dish towel.
Garnish the dish with fresh herbs (such as chopped fresh parsley) for a bright burst of color and flavor.

Square overhead shot of garlic parmesan zucchini casserole on a dinner table

What can you do with a ton of zucchini?

Here are a few of our favorite ways to take advantage of a bounty of fresh zucchini:

Square featured image of an overhead shot of a white dish full of zucchini casserole

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