Name: Zucchini Casserole Recipe
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American
Ingredients: 9 cups shredded zucchini about 2 ½ lbs. whole zucchini; 1 ½ teaspoons salt; 2 teaspoons olive oil; 1 small yellow onion finely diced; 3 cloves garlic minced; 3 large eggs whisked; ¼ cup heavy cream; 1 teaspoon Dijon mustard; 1 ¼ cup panko breadcrumbs; 1 cup shredded Parmesan cheese; ½ teaspoon EACH: oregano, basil, garlic salt, parsley; ¼ teaspoon EACH: paprika, black pepper; 1 ¼ cups shredded cheddar cheese for the top of the casserole; ¼ cup panko breadcrumbs; 1 tablespoon butter melted

Jump to Recipe·5 from 27 reviews

If you’re looking for a side dish that absolutely steals the show, this Zucchini Casserole is it! Packed with perfectly seasoned zucchini, melty cheese, and crowned with a crunchy, golden panko topping, it’s the kind of recipe you’ll want to make again and again. Every forkful is deliciously savory and comforting, with a texture that’s hearty enough to double as a main dish. Trust me, whether you’re trying to use up garden zucchini or hoping to win over a picky eater, this irresistible bake is destined to become a go-to favorite!

Zucchini Casserole Recipe - Recipe Image

Ingredients You’ll Need

Gathering your ingredients for Zucchini Casserole is truly a breeze, and each one plays a starring role. From the brightness of fresh zucchini and aromatic onion, to the creaminess of cheeses and a tailor-made crunchy topping, every component brings the whole dish together in spectacular fashion.

Zucchini: For that tender texture and subtly sweet flavor, freshly shredded zucchini is the heart of this casserole.
Salt: Sprinkling salt on the zucchini draws out excess moisture, keeping your casserole from turning soggy.
Olive Oil: A splash helps soften the onions and garlic and adds a subtle richness.
Yellow Onion: Finely diced for a gentle sweetness throughout each bite.
Garlic: Minced fresh for savory depth and irresistible aroma.
Eggs: Whisked eggs help bind the casserole together and add richness.
Heavy Cream: Just a little creates a lush, creamy consistency in the filling.
Dijon Mustard: A secret ingredient that adds a tangy kick, elevating the overall flavor.
Panko Breadcrumbs: Both inside and on top, they provide irresistible crunch and body.
Parmesan Cheese: Nutty and salty, Parmesan is the foundation of the cheesy flavor.
Dried Oregano, Basil, Garlic Salt, and Parsley: These herbs create a perfectly balanced Italian-inspired seasoning mix.
Paprika & Black Pepper: Slightly smoky and peppery, they round out the flavor without overpowering it.
Cheddar Cheese: Shredded for gooey, melty goodness across the top.
Butter: Melted and mixed with more panko for the crunchiest, golden crust.

How to Make Zucchini Casserole

Step 1: Prep the Zucchini

Start by shredding your zucchini (skin on, unless you’re dealing with a massive one) and piling it up in a colander. Sprinkle it generously with salt, top it with paper towels, and let it sit for at least 15 minutes. This little pause is essential—it lets the salt draw out excess water, ensuring your casserole bakes up tender, not watery.

Step 2: Sauté the Aromatics

In a skillet, heat up the olive oil over medium warmth. Toss in your diced onion and cook until it’s softened and sweet, about five minutes. Add in that fragrant garlic and stir for a couple more minutes. Your kitchen should already be smelling incredible! Remove from heat and set aside.

Step 3: Squeeze & Combine

Give your zucchini a good press with clean paper towels to release as much excess liquid as possible—you want it damp, but not dripping. In a large mixing bowl, combine the zucchini with your sautéed onions and garlic, whisked eggs, heavy cream, Dijon mustard, panko, Parmesan, all the herbs and spices, and mix it well. Every scoop should be studded with flecks of cheesy, herby goodness.

Step 4: Layer in the Casserole Dish

Lightly grease a 9 x 13-inch casserole dish, then spread your zucchini mixture evenly into the pan. Shower the top with shredded cheddar cheese, spreading it from corner to corner for that gooey, golden finish.

Step 5: Bake Covered

Cover the dish with foil and bake in your preheated 375°F oven for 35 minutes. This step lets all the flavors meld together and sets up the casserole within.

Step 6: Add the Crunchy Topping

While it bakes, mix together your melted butter and more panko breadcrumbs. After the initial bake, sprinkle this buttery combo evenly over the casserole. Then, return it to the oven uncovered for another 15 minutes. If you love an extra-crunchy top, place it under the broiler for 1-2 minutes—just keep an eagle eye on it!

Step 7: Rest & Serve

Once it’s out of the oven, let your Zucchini Casserole rest for five minutes. This helps it set, making serving a breeze—and letting those cheesy aromas really shine!

How to Serve Zucchini Casserole

Garnishes

This casserole loves a little extra attention! Scatter some fresh chopped parsley or basil over the top for a burst of color and freshness. If you’re feeling decadent, a sprinkle of extra Parmesan or even a few toasted pine nuts will make this dish feel truly special.

Side Dishes

Pair your Zucchini Casserole with simply grilled chicken, roasted pork chops, or a big summer salad for a vibrant, satisfying meal. It’s also a great vegetarian main when served alongside buttery rice, quinoa, or a hearty loaf of crusty bread. The versatility truly impresses every time!

Creative Ways to Present

For a showy table moment, spoon the casserole into individual ramekins or mini casserole dishes before baking. It also makes an amazing brunch centerpiece—top with a poached egg or a dollop of sour cream for a twist. And don’t be afraid to cut big, generous squares for serving family-style at your next gathering.

Make Ahead and Storage

Storing Leftovers

Leftover Zucchini Casserole keeps beautifully—just let it cool, then transfer slices to an airtight container. It’ll stay fresh in the fridge for up to three days, and honestly, it’s just as tasty eaten cold as it is reheated!

Freezing

If you don’t finish it all (good luck!), you can freeze portions for up to three months. Wrap individual squares tightly in plastic wrap, then in foil, and tuck them into a freezer-safe bag. Label and date for easy future craving management!

Reheating

To reheat, place leftovers in a lightly greased dish and bake uncovered at 350°F for 20-25 minutes, or until warmed through. If you’ve frozen it, thaw overnight in the fridge first, then reheat as above for best results. The crunchy top will crisp up again and the cheese will melt perfectly.

FAQs

Can I use yellow squash in this Zucchini Casserole?

Absolutely! You can swap in yellow squash for part (or all) of the zucchini. The flavor and texture will stay just as lovely, and you’ll get even more color in each bite.

What’s the best way to shred zucchini for this recipe?

I recommend using the large holes on a box grater, keeping the skin on for extra nutrition and color. If your zucchini is jumbo-sized and the skin seems tough, just peel it first.

Can I make Zucchini Casserole ahead of time?

It’s best baked immediately after assembling, as the salted zucchini keeps releasing water and can change the texture if left too long. If you must prep ahead, assemble everything except the eggs and cream, then mix those in right before baking.

How can I turn this into a main dish?

Toss in extra protein like cooked ground sausage, shredded chicken, or even black beans before baking. You can also add extra veggies—just add an extra egg for extra binding power!

Why is my casserole watery?

This usually happens if the zucchini wasn’t squeezed enough before mixing. Don’t worry—the flavors are still delicious, and the casserole will continue to set as it cools. Next time, press more moisture out for a firmer result.

Final Thoughts

If you haven’t tried making Zucchini Casserole yet, you are in for an absolute treat. It’s simple, cozy, and filled with flavor—the kind of dish that draws everyone back for seconds. Give it a spot on your table soon, and get ready to collect rave reviews from family and friends!