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This easy zucchini casserole is a hearty, cheesy, and comforting family dinner made with fresh zucchini, a bread crumb topping and plenty of gooey cheese. A quick and easy zucchini casserole recipe that’s perfect for using up fresh summer zucchini!
Garden zucchini coming out your ears? This zucchini casserole turns a whopping 9 cups of shredded zucchini into one seriously delicious side dish. Garlic, herbs and 3 different cheeses bring the flavor, while a buttery panko topping adds that golden CRUNCH we all know is the best part.
Table of Contents
- Ingredients You’ll Need
- How Do You Keep Zucchini Casserole From Getting Watery?
- Do You Need to Peel Zucchini for Casserole?
- Variations and Substitutions
- What to Serve with Zucchini Casserole
- Can You Make Zucchini Casserole Ahead of Time?
- Storing + Reheating
- Tips for the Best Zucchini Casserole
- More Zucchini Recipes:
- Watch How This Zucchini Casserole is Made…
- Cheesy Zucchini Casserole Recipe
And don’t worry—we’ve got a simple trick for getting rid of all that extra zucchini moisture so you don’t end up with a puddle at the bottom of your casserole.
I planted ONE zucchini plant this year. One. I thought I was being smart because zucchini plants are notorious for producing more squash than any human could possibly eat. Well, I picked 10 zucchini and there were still 21—yes, TWENTY-ONE—on the dang plant! What?!
Clearly, I needed a recipe that could put a serious dent in my zucchini situation, and this casserole was the winner!
It’s an easy vegetable side dish for Sunday dinner, summer BBQs or potlucks—and apparently the answer to one wildly overachieving zucchini plant.
Why You’ll Love This Zucchini Casserole
- Uses a TON of zucchini: 9 cups of shredded zucchini disappear into one delicious casserole. Hello, summer garden!
- Creamy + crunchy: The tender, cheesy zucchini filling gets topped with buttery panko for the best contrast in texture.
- BIG flavor: Zucchini can be a little blah on its own, so we’re bringing in sautéed onion and garlic, oregano, thyme, basil and paprika. No boring veggies here!
- No soggy casserole: Salting and draining the shredded zucchini first removes excess moisture so you don’t end up with zucchini soup.
- THREE kinds of cheese: Parmesan goes into the casserole while cheddar and mozzarella create that irresistible cheesy top.
- Easy side dish: It’s simple enough for a weeknight but totally at home alongside a Sunday roast or on a holiday table.
Ingredients You’ll Need
- Shredded Zucchini: You’ll need about 2 ½ pounds, or 9 cups once shredded. Don’t peel it! The skin is tender and adds color.
- Onion + Garlic: Sautéing them first takes away the raw bite and adds so much more flavor to the casserole.
- Eggs + Sour Cream: These bind everything together and give the filling its creamy texture.
- Dijon Mustard: Just a teaspoon adds a little tang and depth without making the casserole taste like mustard.
- Panko Breadcrumbs: Panko goes both inside the casserole to help with the texture and on top for that irresistible buttery crunch.
- Cheese: Parmesan adds salty, nutty flavor to the filling while cheddar and mozzarella make the top cheesy and gooey.
- Herbs: Oregano, thyme and basil give the zucchini tons of flavor. Fresh herbs are fantastic here when the garden is going crazy!
How Do You Keep Zucchini Casserole From Getting Watery?
Zucchini is LOADED with water, and once it heats up in the oven, all that water has to go somewhere. If we don’t remove some of it first, it ends up pooling in the bottom of the casserole.
The trick is to salt the shredded zucchini before baking. Salt pulls moisture from the zucchini while it rests in the colander. After 15 minutes, press the zucchini firmly with paper towels to soak up as much liquid as you can.
PRO TIP: Really press on it! You’re not going to hurt the zucchini, and the more moisture you remove now, the better the texture of your casserole will be later.
Do You Need to Peel Zucchini for Casserole?
Nope! There’s no need to peel zucchini before shredding it for this casserole. Zucchini skin is thin and tender, and leaving it on gives the casserole little flecks of gorgeous green color.
Variations and Substitutions
We love this zucchini casserole exactly as written, but here are a few simple ways to play with the flavors::
- Yellow squash: Replace part of the zucchini with shredded yellow summer squash.
- Greek yogurt: Plain full-fat Greek yogurt can be used in place of the sour cream.
- Different cheese: Try Gruyère, Monterey Jack or pepper Jack in place of the cheddar or mozzarella.
- Cracker topping: Swap the panko topping for crushed buttery crackers.
- Fresh herbs: If your herb garden is going crazy too, use fresh oregano, thyme and basil instead of dried.
- Add a little heat: A pinch of red pepper flakes would be delicious with the garlic and Parmesan.
What to Serve with Zucchini Casserole
This zucchini casserole is one of those side dishes that goes with practically everything! Serve it with grilled chicken, steak, pork chops or a Sunday roast for dinner. In the summer, we love it alongside burgers or ribs with fresh fruit or a big summer salad.
Can You Make Zucchini Casserole Ahead of Time?
Yes, but we recommend prepping the components rather than assembling the whole casserole ahead of time. Zucchini continues to release moisture as it sits, so you’ll get the best texture when the casserole is assembled just before baking.
To get a head start, shred, salt and drain the zucchini and sauté the onion and garlic. Store them separately in airtight containers in the refrigerator, then assemble and bake when you’re ready.
Storing + Reheating
Storing: Let leftover zucchini casserole cool completely, then cover tightly or transfer to an airtight container. Store in the refrigerator for 3-4 days.
Reheating: For the crispiest topping, reheat it in a 350°F oven until warmed through. Individual servings can also be microwaved, but you’ll lose some of that glorious panko crunch.
Freezing: I don’t recommend freezing zucchini casserole. Zucchini already contains so much moisture that the texture can become watery and mushy after freezing and thawing.
Tips for the Best Zucchini Casserole
- Don’t peel the zucchini. There’s no need, and those little flecks of green are gorgeous.
- Drain, drain, drain! The more moisture you remove from the zucchini, the better the final texture.
- Shred your own cheese. It melts better than the pre-shredded stuff.
- Don’t add the panko too early. Adding the buttery breadcrumbs toward the end keeps them crispy instead of soggy.
- Give it 5 minutes to rest. Letting the casserole sit briefly after baking helps everything set up before serving.
- Broil for extra crunch. A minute or two under the broiler gives the panko that gorgeous golden finish—just watch it closely!
So when the garden starts handing you zucchini faster than you can possibly eat it, you know what to do! This zucchini casserole puts a whopping 9 cups to delicious use with layers of savory herbs, garlic and THREE kinds of cheese.
But that buttery crispy panko topping? That’s what takes it over the top! Creamy and cheesy underneath, golden and crunchy on top, and absolutely NO zucchini swimming pool at the bottom. 🙌
Maybe planting that zucchini plant wasn’t such a bad idea after all…
More Zucchini Recipes:
- Cheesy Zucchini Pasta
- Italian Stuffed Zucchini Boats
- Zucchini Corn Chowder
- Zucchini Lasagna
- Sausage and Zucchini Casserole
Watch How This Zucchini Casserole is Made…
Cheesy Zucchini Casserole
Ingredients
- 9 Cups Zucchini, shredded, about 2 ½ lbs. whole zucchini
- 1 teaspoon Salt
- 2 teaspoons Olive Oil
- 1 Yellow Onion, small, finely diced
- 4-5 Cloves Garlic, minced
- 2 Eggs, large, whisked
- ⅓ Cup Sour Cream
- 1 teaspoon Dijon Mustard
- 1 ¼ Cup Panko Breadcrumbs
- ¾ Cup Parmesan Cheese, shredded
- 1 ½ teaspoons Dried Oregano, (or 2 teaspoons fresh)
- ½ teaspoon Dried Thyme, (or 1 teaspoon fresh thyme leaves)
- 1 ½ teaspoons Dried Basil, (or 1 Tablespoon chopped fresh basil)
- ¼ teaspoon Smoked Paprika
- Black Pepper
Topping
- ¾ Cup Cheddar Cheese, shredded
- ¾ Cup Mozzarella, shredded
- ⅓ Cup Panko Breadcrumbs
- 1 Tablespoon Butter, melted
Instructions
- Preheat oven to 375℉ and use nonstick spray to grease a 9×13" pan.
- Shred the zucchini and transfer it to a colander. Sprinkle with a light layer of salt, about 1 teaspoon. Top with paper towels and let sit for 15 minutes (or longer) while you measure out remaining ingredients.9 Cups Zucchini, 1 teaspoon Salt
- Saute: Heat olive oil in a small skillet over medium heat. Add the onions and soften for 5 minutes. Add the garlic and stir occasionally for 2 minutes. Remove and set aside.2 teaspoons Olive Oil, 1 Yellow Onion, 4-5 Cloves Garlic
- Using paper towels, press down and absorb all excess moisture from the zucchini.
- Transfer to a large bowl along with the sauteed onions and garlic, whisked eggs, sour cream, mustard, 1 ¼ cup panko, parmesan cheese, and seasonings/herbs. Stir to combine.2 Eggs, ⅓ Cup Sour Cream, 1 teaspoon Dijon Mustard, 1 ¼ Cup Panko Breadcrumbs, ¾ Cup Parmesan Cheese, 1 ½ teaspoons Dried Oregano, ½ teaspoon Dried Thyme, 1 ½ teaspoons Dried Basil, ¼ teaspoon Smoked Paprika, Black Pepper
- Transfer to a lightly greased 9×13-inch casserole dish. Top with cheddar and mozzarella cheese.¾ Cup Cheddar Cheese, ¾ Cup Mozzarella
- Cover and bake for 35 minutes. Remove from the oven and proceed with topping.
Topping
- Combine the 1/3 cup panko and melted butter for the topping and sprinkle it over the casserole.⅓ Cup Panko Breadcrumbs, 1 Tablespoon Butter
- Bake uncovered for 15 minutes.
- If desired, broil at 425℉ for 1-2 minutes to add more color to the top.
- Remove and let stand for 5 minutes then serve.
Recipe Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
