An easy side dish that pairs beautifully with just about any family meal! The garlic parmesan zucchini casserole features fresh shredded veggies, garlic, and onion baked with three types of cheese and finished with a buttery, crispy, Parmesan breadcrumb topping.
Table of Contents
If you have a ton of fresh zucchini, check out some of our other favorite zucchini recipes, such as sauteed zucchini, this easy snickerdoodle zucchini bread, a batch of one-bowl zucchini muffins, and a loaf of zucchini bread!
How to Make Zucchini Casserole | 1-Minute Video
easy, delicious and a good low carb veggie dish. I added a heavy splash of hot sauce and some freshly grated nutmeg to balance all the cheese. this recipe is a keeper
– Sheba
Why You’ll Love this Recipe
- Easy. If you can stir together some simple ingredients, then you can make this easy zucchini casserole recipe. With about 15 minutes of prep time, the dish is ready for the oven!
- Flavorful. On its own, zucchini can be a very neutral, bland vegetable. This casserole is anything but boring, however! The veggies are seasoned with plenty of garlic, three different types of cheese, and a crunchy, buttery topping.
- Versatile. The zucchini casserole works well as a vegetarian entree, but also serves as a delicious side side for almost any main course. Offer it with your Easter or Christmas ham, alongside a Thanksgiving smoked turkey breast, with marinated grilled shrimp, or with grilled bbq chicken breast, grilled pork chops, and grilled hamburgers throughout the summer months.
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. I use a handheld box grater to shred my zucchini, but you can also put it through a food processor if you prefer. There’s no need to peel the zucchini.
- 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. I use sweet onion, but yellow onion or white onion both work fine.
- 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. 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.
- Panko breadcrumbs and melted butter: combine the panko bread crumbs with the Parmesan and melted butter to form the crispy, golden brown topping. 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).
Directions
This old fashioned zucchini casserole is an easy recipe to take advantage of an abundance of fresh summer veggies. You’ll find detailed directions in the recipe card below, but here’s the overview:
- Place the zucchini in a colander, sprinkle it with salt, and allow it to sit for about 10 minutes (this will help draw out some of the water so that the zucchini doesn’t make your casserole watery). After 10 minutes, squeeze out the moisture from the zucchini. A dish towel works really well to wring out all of that excess water.
- Combine the drained zucchini, onion, garlic, eggs, some of the Parmesan cheese, mozzarella cheese, and cheddar cheese in a small, greased baking dish.
- Bake uncovered for 20 minutes.
- Make the topping by combining melted butter with breadcrumbs and additional Parmesan cheese.
- Sprinkle the breadcrumbs over the zucchini mixture and return the pan to the oven.
- Bake for about 5-10 more minutes, or until the zucchini is tender and the top is golden brown and crispy.
- Garnish the dish with fresh herbs (such as chopped fresh parsley, fresh basil, or fresh thyme) or with a squeeze of fresh lemon juice for a bright burst of color and flavor.
Serving Suggestions
This versatile casserole pairs nicely with just about any meat, seafood, or pasta. We love the cheesy zucchini casserole alongside grilled salmon or grilled scallops, with crispy fried chicken, grilled chicken, or baked chicken thighs, maple Dijon chicken, with marinated pork tenderloin, alongside a Southern meatloaf, with cozy stuffed shells, this turkey Sloppy Joes recipe, with pasta and marinara sauce, a tomato sandwich, or with a veggie pizza. Then, add a strawberry jello salad or easy banana pudding for dessert.
I made this last night for 8 guys who were working on my house. I doubled the recipe and you would have thought that it was the best thing these guys have ever eaten. It was all devoured by the end of the meal! Definitely going to make this again!
– JJ
Preparation and Storage Tips
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, or warm individual servings in the microwave for 30-60 seconds, or until heated 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.
Recipe Variations
- Use a combination of yellow squash and zucchini, or replace all of the zucchini with yellow summer squash. Shredded carrots would also be a nice addition.
- 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.
- Toss the breadcrumbs with olive oil instead of melted butter for a slightly different flavor.
- Add some ground black pepper or crushed red pepper for a zestier kick. Italian seasoning would also be a nice addition to the filling.
- For a tasty twist, try adding coarsely grated zucchini to this dump-and-bake vegetable casserole with rice.
Made this tonight, it is awesome, love It! Will keep this recipe for future use.
– Karen
More Zucchini Casserole Recipes
Zucchini Pie
50 minutes mins
Chicken Zucchini Casserole
55 minutes mins
Did you make this recipe?
If you enjoyed this recipe, please leave a comment with a 5-star review at the bottom of the post. Thank you!
Watch How to Make It
Garlic Parmesan Zucchini Casserole
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 (about 3 cloves)
- 2 large 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 salted butter
Instructions
- Preheat oven to 375°F. Grease a 1 ½-quart baking dish; set aside.
- 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. TIP: In order to make sure that you get most of the water out of the zucchini (and avoid a runny casserole), 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!
- In a large bowl, combine zucchini, onion, garlic, eggs, ½ cup Parmesan cheese, mozzarella cheese, and cheddar cheese. Gently press the mixture evenly into the prepared dish.
- Bake uncovered for 20 minutes.
- Meanwhile, in a small bowl, pour melted butter over breadcrumbs and 2 tablespoons of Parmesan cheese. Stir until completely combined.
- After 20 minutes, remove zucchini from the oven. Sprinkle buttered breadcrumbs over the zucchini and return the dish to the oven. Continue baking for about 5-10 more minutes, or until the top is golden brown and crispy.
Notes
- I use a handheld box grater to shred my zucchini, but you can also put it through a food processor if you prefer.
- Add some ground black pepper or crushed red pepper for a zestier kick. Italian seasoning would also be a nice addition to the filling.
- Garnish the dish with fresh herbs (such as chopped fresh parsley) for a bright burst of color and flavor.
Nutrition
This post was originally published in February, 2017. It was updated in June, 2024.
Is this easy to make before (maybe the morning of?) and then cook later on for dinner?
Hi, Kristin! Yes, you can definitely make it ahead of time. Your best bet would be to bake it through Step 4 in advance. Then freeze or refrigerate the baked zucchini until you’re ready to finish it. Then you just need to top it with the breadcrumbs and finish baking when you’re ready to serve. Hope that helps! 🙂
I am allergic to eggs. What is a good alternative for me to use in this recipe??
Hi, Alicia! I’m honestly not sure. I haven’t tested this recipe without the eggs, and the eggs are important for holding the casserole together. If you omit the eggs, you would want to find something else to act as a binder. I know that there are some commercially made egg replacers, which are often made with potato starch, tapioca starch and leavening. These are used in baking, but can probably be used here, too. Another option that some folks use in baking is to replace eggs with “flax eggs.” Again, I haven’t actually tried this, but you could see how it goes if you’re curious. To replace one egg, whisk together 1 tablespoon (7 grams) of ground chia or flaxseeds with 3 tablespoons (45 grams) of water until fully absorbed and thickened.
Hope that helps!
Thanks you I may someday have to experiment with that egg substitute. Can you taste the egg in the dish, or is it just binding like as it is in a cake, where as the cake does not taste like egg.
Hi, Alicia! The flavor of the egg doesn’t stand out much in this dish. It’s more of a binder in this case. 🙂
I made this dish and absolutely loved it. However, I did not shred the zucchini… I cubed it. Even though I used salt, I did not get water from it. By keeping it in the oven 10 more minutes before the breadcrumbs it cooked thoroughly and it was not watery. ( the water helped cook the cubes). Then I put the breadcrumbs on and back in the oven. It was delicious!
That’s a great tip, Meredith! Glad that you enjoyed it!
I have heard that the liquid from canned garbanzo beans can be substituted for eggs.
I love zucchini but some of my family members not so much……they loved this recipe!!!!!!
Oh, good! I’m so glad to hear that, Cris. Thanks for coming back here to let me know. 🙂
You’re the one who is allergic. Don’t you have this figured out by now? I have food, allergies, but I don’t expect recipe inventors to accommodate them all. I expect myself to have some knowledge, and if I don’t, I’m going to some research. I don’t get why everybody thinks that every recipe inventor should cater to their every single individual quirk.
easy, delicious and a good low carb veggie dish. I added a heavy splash of hot sauce and some freshly grated nutmeg to balance all the cheese. this recipe is a keeper
Sounds perfect! Thanks, Sheba!
This casserole is fabulous. I made a smaller version because I didn’t have enough zucchini but will now be making full recipes often!
Thank you, Kelly! 🙂
I really enjoyed this zucchini casserole. I was afraid that it would have an overwhelming zucchini flavor, but it didn’t. Although, it did have a ton of flavor! The onions added a nice crunchy texture. And the cheese was the icing on the cake.
Yumyumyumyum!
Thanks for your note, and I’m so glad that you enjoyed it! The zucchini is very mild, isn’t it? I think that’s why my kids and husband love it so much. 🙂
I just want to say how delicious this dish was. I made it while visiting my daughter because she loves squash. It was a huge hit. This pin on my board is pinned repeatedly everyday. There must be lots of zucchini lovers out there!!! Thanks so much for your creativity!!!
Hi, Laurie! Thanks so much for your kind note and for letting me know. A good zucchini recipe is always helpful to have on hand — especially in the summer. So happy that your family enjoyed it!
What can I replace the eggs with? May daughter is allergic to eggs.
Thanks,
Kimberly
Hi, Kimberly! I’ve never made this dish without eggs, so I’m not sure how it will work with different ingredients. That said, I do know that vegans and other folks with egg allergies often substitute regular eggs with “flax eggs.” Have you used flax eggs before? To make a flax egg, just mix one tablespoon ground flaxseed meal with three tablespoons of water. Mix together, and let sit in your fridge for 15 minutes to set up and thicken. That’s equivalent to one egg, so just double or triple depending on how many regular eggs you’re replacing.
Thanks! I never heard of that before. I will have to buy some – thanks!!
You’re welcome! 🙂
okay so I made it last night…overall I liked it. I tried the “flax egg ” mixture instead of the egg like you suggested. Since I’ve never made this dish before I’m not sure what the consistency should be like, but I think mine was more on the wet side. I’m not sure if the zucchini wasn’t drained enough or if it was the “flax egg”.
I also think I put too much garlic in…I think 1 tablespoon might be too much.
My daughter (who is allergic to eggs) liked it in the beginning then said she didn’t like it. But she almost finished her small bowl of it. Again, I think it was the overpowering garlic taste.
Either way I would make it again with less garlic and have her try it again!
Hi, Kimberly! I’m glad to know that it worked out overall. When it comes to draining the zucchini, I like to wrap it in a dish towel and literally wring it dry — squeezing it as hard as I can until no more water is coming out. You would be amazed by how much moisture is released, and I think that you’ll find the casserole is not watery at all if you do it this way. Hope that helps, and thanks for sharing your feedback! 🙂
I have done it with out eggs and it’s delicious
Awesome! Thanks, Carrie!
Made this tonight, it is awesome, love It! Will keep this recipe for future use.
Perfect! Thanks, Karen — I’m so glad that you enjoyed it! 🙂
I made this for supper last night and it is amazing!! A hit with the whole family! This is a keeper recipe! Thank you!!!!
I’m so glad to hear that the family enjoyed it, Cheryl! Thanks for letting me know!
I’ve been looking for a new dish to take to Thanksgiving dinner. This sounds like a yummy, updated version of a classic family dish!
Wonderful! Enjoy, Jen! It’s one of our favorites! 🙂
Made this tonight for the first time and I really liked it. I grated 2 cloves of garlic and did find the flavor on the strong side but I like garlic, so I was ok with it. I also know grating garlic releases a stronger flavor so that might be part of it. Great recipe!!!
Thanks, Heidieh! 🙂
If planning to double the recipe, would you also double the time in oven? Very excited to try!
Hi, Kristelle! No, I wouldn’t double the time in the oven. You might need to add a little bit of time to accommodate the larger dish, but probably not much. I would bake it uncovered for 25-30 minutes before adding the buttered breadcrumbs on top. Then return to the oven for the final 5-10 minutes. If that still doesn’t seem long to heat it through, you can cover the top lightly with foil (to prevent the top from getting too brown) and leave it in the oven for a few more minutes, as necessary. 🙂
plan on making this in a 9×13 dish for Easter Sunday…..I was going to almost double amounts ….cooking time suggestions?
Hi, Bernie! Doubling the ingredients for a 9 x 13 dish should work perfectly. The cooking instructions should remain largely the same; although you might want to add about 5-10 minutes to the overall cooking time to make sure that it’s properly heated through. Just check it after the first 20 minutes and see if the zucchini mixture looks adequately warmed through. If not, pop it back in the oven for 5 more minutes before adding breadcrumbs to the top. Hope you love it!
I made this last night for 8 guys who were working on my house. I doubled the recipe and you would have thought that it was the best thing these guys have ever eaten. It was all devoured by the end of the meal! Definitely going to make this again!
Wonderful! It’s a huge WIN when a veggie dish gets the stamp of approval from a group of guys! 🙂
This recipe was wonderful, I followed the recipe exactly minus the onions and when you follow directions its comes out exactly the way it should be , no ruuny mess over here lol.
Perfect! So glad that it worked, Robin! 🙂 Thanks for your note!
I made this tonight and it was so good! My husband even commented on how great it tasted especially with so much zucchini in it. Will be making this again, as our family of 3 devoured pretty much the whole thing in one sitting. Thanks for the delicious recipe!
Wonderful! Love when the husbands approve of veggie dishes! 🙂
Can you shred the zucchini instead of grating it? It seems like it would take a very long time to grate the zucchini.
Yes, I think that would probably work fine.
Thank you, Blair!
How did shredding vs grating work out? Glad you asked as when I read grated, I assumed shredded. Agree grating would take forever!
Also wanted to make ahead but wondering if 10 minutes after adding pinko would reheat it up sufficiently.
Hey, Karen! I would think that it will likely need about 15-20 minutes to reheat completely, so maybe sprinkle on the topping towards the end.
Do you measure the zucchini before or after you squeeze it out? Kind of confused. Sounds good tho.
Measure it before squeezing it out. 🙂
I made this last night to go with grilled lamb loin chops.
I added a cup of cooked white rice to the mixture and used lowfat cheeses.
It was excellent!!! My husband ate two helpings. I will definitely make this again.
Oh, great idea to add the rice! Thanks, Nancy!
I have made this recipe 3 times already! Great stuff!
1st time) Made as recipe states and it was a hit, even with those who thought they didn’t like zucchini.
2nd time) Tried being creative and tried squeezing the zucchini with a potato ricer – turns out it does NOT work as good as an old fashioned tea towel. Lesson learned.
3rd time) Went back to the original way! Having some health issues, so I reduced the cheese and added some already cooked quinoa. Eating it now and it’s fabulous. Thanks so much!
Thanks, Leela! I’m so glad that you love it, too. I just made it last week and I enjoyed some leftovers for lunch the next day. It’s so good that I could eat it like an entree! Love the idea of adding quinoa to make it more filling!
I have cups and cups of frozen zucchini from my garden last year. I’m trying to use it up and found your recipe. Do you think this recipe will work if I use frozen zucchini?
Hi, Monique! I think it would probably work fine, but I would definitely thaw the zucchini first and really make sure to squeeze out any excess liquid. 🙂
Thinking about adding precooked ground turkey to the dish for an all in one. Thoughts? TIA
That sounds like a delicious idea! I bet it will work really well. Let me know if you give it a try, Adair!
Oh my dammmmit! Deeeelicious! !
Hah! Thank you! 🙂
Made this using yellow squash and it was delicious. Topped it off with Frenchs onions and Frenchs Jalapeno. Gave it a nice kick. Will make again!!!
YUM! So glad that you enjoyed it, Renee!