Easy zucchini casserole dinner

Looking for a side dish that actually gets cleaned off the plate? This cheesy zucchini casserole has been my go-to since Sarah went through her "I don't like green vegetables" phase last summer. Honestly, watching her ask for seconds was the moment I knew this recipe was a keeper.

Jump to:

• Cheesy Zucchini Casserole

I started making this back when my mom would send me home from her place with grocery bags full of zucchini from the farmer's market on 79th Street. You know how it goes... you buy two zucchinis, you blink, and suddenly you have nine. I needed something that would use them all up in one shot, and this casserole was born out of pure necessity (and a tiny bit of desperation).

The thing is, most veggie casseroles taste like sad, soggy disappointment. Not this one. We're talking golden cheddar on top, a crunchy panko crust, and a creamy inside that holds together beautifully. If you love simple veggie sides, you might also try my healthy baked zucchini fritters for a low-carb option that pairs perfectly with weeknight meals.

Why You Will Love This Zucchini Casserole

Here's what makes this recipe a regular in my Manhattan kitchen:

• Quick prep time at just 15 minutes of hands-on work
• Family-friendly flavor that even picky eaters will eat (Alex approved!)
• Cheesy and creamy with that golden crust everyone fights over
• Works as a side or a main depending on how hungry everyone is
• Uses simple ingredients you probably have right now
• Great way to use up summer squash when your garden goes wild

Donald usually rolls his eyes at veggie casseroles, but he ate three helpings of this last Tuesday. Three! That's basically a five-star review from my husband.

Simple Ingredients for the Best Zucchini Casserole

Here's everything you need. Nothing fancy, nothing weird, just real food:

For the Filling

• 9 cups shredded zucchini (about 2 ½ pounds 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

For the Crunchy Topping

• ¼ cup panko breadcrumbs
• 1 tablespoon butter, melted

A quick note on the cheese... please shred it yourself if you can. Those pre-shredded bags have anti-caking stuff that makes melting weird. Sarah and I made this once with bagged cheddar and the texture was just off.

How to Make This Cheesy Zucchini Casserole

The first time I made this, I rushed the moisture step and ended up with soup. Learn from my mistakes, friends. Here's the right way to do it.

Prep the Zucchini

1. Preheat your oven to 375°F.
2. Shred the zucchini (skin on is fine, unless they're those giant baseball bat sized ones) and put it in a colander.
3. Sprinkle the salt over the top, layer paper towels on it, and let it sit for at least 15 minutes. This pulls out the water that would otherwise ruin your casserole.

Cook the Aromatics

4. Heat olive oil in a small skillet over medium heat.
5. Add the diced onion and cook for about 5 minutes until soft and a little golden.
6. Toss in the garlic and cook for 2 more minutes. Take it off the heat and set it aside.

Squeeze and Mix

7. Press paper towels firmly into the zucchini to soak up the moisture. You want it damp but not dripping. Honestly, this recipe is super forgiving so don't stress about getting it perfect.
8. Move the zucchini to a big bowl.
9. Add the cooked onions and garlic, whisked eggs, heavy cream, Dijon, 1 ¼ cup panko, Parmesan, and all the seasonings.
10. Stir everything together until it looks well combined.

Bake to Golden Perfection

11. Pour the mixture into a lightly greased 9 by 13 inch casserole dish.
12. Sprinkle the shredded cheddar evenly across the top.
13. Cover with foil and bake for 35 minutes.
14. While it bakes, mix the ¼ cup panko with the melted butter in a small bowl.
15. Take the foil off, sprinkle the buttery panko mixture on top, and bake uncovered for 15 more minutes.
16. Want extra color? Broil at 425°F for 1 to 2 minutes. WATCH IT THE WHOLE TIME. I burned the top once because I walked away to grab a drink. Never again.
17. Let it rest for 5 minutes before scooping. This helps it set up beautifully.

How to Store and Reheat Zucchini Casserole

Leftovers? You're in luck. This stuff keeps really well.

Pop any extras into an airtight container and store in the fridge for up to 4 days. The flavors actually get even better on day two, which is wild to me.

For freezing, let it cool completely first. Wrap individual portions in plastic wrap, then foil, and freeze for up to 2 months. Thaw overnight in the fridge before reheating.

To reheat, just put it in a 350°F oven for about 15 minutes until warmed through. The microwave works too but the topping loses its crunch. Sarah eats it cold straight from the fridge sometimes... that girl has weird food habits.

Tasty Variations for Your Zucchini Casserole

Want to switch things up? Here are some ideas I've tried over the years:

• Yellow squash swap: Use yellow squash instead of zucchini, or mix them half and half for pretty color
• Meat lover's version: Brown a pound of Italian sausage and stir it in to make it a full meal
• Different cheeses: Mozzarella, Monterey Jack, or pepper jack all work great
• Add some heat: A pinch of red pepper flakes wakes everything up
• Bacon makes it better: Honestly, doesn't bacon make everything better? Crumble a few crispy strips on top
• Herb it up: Fresh basil or thyme on top after baking adds a pretty pop

Do you have a jar of sun-dried tomatoes hiding in your fridge? Chop them up and toss them in. Trust me on this one.

Speaking of zucchini ideas, my kids also love these crispy air fryer zucchini chips with parmesan as a snack. They disappear in minutes.

Frequently Asked Questions About Zucchini Casserole

Can I make zucchini casserole ahead of time?

Yes! You can put the whole thing together (minus the panko butter topping) up to 24 hours ahead. Cover it with plastic wrap and keep it in the fridge. When you're ready to bake, let it sit on the counter for 20 minutes, then add the topping right before baking. Add about 5 extra minutes to the cook time since it's starting cold.

How do you keep zucchini casserole from getting watery?

The salt and drain step is everything. Sprinkling salt on the shredded zucchini pulls out the water, and pressing it with paper towels removes even more. Don't skip this part! I learned the hard way that wet zucchini equals a soupy casserole. Also, letting it rest for 5 minutes after baking helps it set up properly.

Can I use yellow squash instead of zucchini in this casserole?

Absolutely. Yellow squash works exactly the same way and tastes almost identical. I sometimes use half and half when both are in season because the color combination looks really pretty on the table. Just make sure to salt and drain it the same way you would zucchini.

What should I serve with zucchini casserole?

This goes with pretty much anything. We love it next to grilled chicken, baked salmon, or a simple roast. It's also great with steak and a big green salad. For a vegetarian dinner, I'll serve it with rice pilaf and roasted tomatoes. Donald likes it alongside grilled Italian sausages... so good.

More Recipes You Will Love

• Stuffed zucchini boats with ground turkey: A heartier zucchini dinner that's a complete meal in one
• Keto zucchini lasagna roll ups: Low carb comfort food that even pasta lovers will enjoy
• Cheesy chicken broccoli rice casserole: Another family favorite casserole for cozy weeknights

Final Thoughts on This Family Favorite

This cheesy zucchini casserole is one of those recipes I keep coming back to because it actually works. It's simple, it tastes amazing, and it makes my whole family happy at the dinner table. Plus, it's a great way to sneak vegetables into Alex without him noticing.

Give it a try this week and let me know how it goes! If your family devours it like mine does, I'd love to hear about it in the comments. And don't forget to save this one to your Pinterest board so you can find it when zucchini season hits.

Print