There’s something undeniably comforting about a warm, cheesy casserole fresh out of the oven—especially when it’s packed with seasonal zucchini, bubbling cheese, and a crispy golden topping. If your garden is overflowing with zucchini or you’re just looking for a no-fuss, flavorful side dish, this zucchini casserole is exactly what you need.

It’s easy enough for a weeknight dinner and crowd-pleasing enough to bring to a potluck. This version is creamy, cheesy, and perfectly seasoned with garlic, onion, and a hint of paprika. Whether you’re feeding picky eaters, sticking to a vegetarian plan, or just want to use up your veggies in the most delicious way possible, this is a go-to recipe you’ll come back to again and again.

Let’s dive into why this casserole is a must-try.

Why You’ll Love This Zucchini Casserole

There’s more to this dish than just zucchini and cheese—it’s the kind of recipe that hits all the right notes: flavor, texture, and simplicity.

Key Benefits

• Ridiculously Easy to Make – No complicated steps or fancy techniques required. Just mix, bake, and enjoy.

• Comfort Food, but Lighter – You get all the cozy vibes of a traditional casserole, but with fresh zucchini as the base.

• Customizable to Your Heart’s Content – Want to add bacon? Go for it. Prefer Gruyère instead of cheddar? Absolutely.

• Kid and Crowd Approved – Even veggie skeptics can’t resist the cheesy, golden top and savory filling.

• Works for Any Meal – Serve it as a side, a vegetarian main, or even a brunch dish with eggs on the side.

Suitable For

• Vegetarians – No meat needed, though it’s easy to add if you’d like.

• Low-Carb Diets – Skip the breadcrumbs and you’ve got a low-carb winner.

• Busy Weeknights – It comes together in under an hour with simple prep.

• Meal Preppers – Assemble it ahead of time and bake when ready.

Ingredients for Zucchini Casserole

This recipe uses pantry staples and fresh produce. No trips to specialty stores required.

Core Ingredients

• Zucchini (4 cups) – You’ll need about two medium zucchinis. Slice them thinly or shred them—both work well. Just make sure to remove excess moisture.

• Onion & Garlic – These bring depth and savory flavor. Finely chop the onion and mince the garlic for best results.

• Cheddar Cheese (1 cup) – Sharp cheddar adds a classic cheesy punch. You can also mix in some mozzarella for extra melt.

• Parmesan Cheese (½ cup) – Adds salty, nutty notes and helps crisp the topping.

• Eggs (2 large) – These bind the casserole together.

• Milk (½ cup) – Whole milk is ideal for creaminess, but you can use 2% or even dairy-free milk.

• Salt, Black Pepper & Paprika – Just enough seasoning to enhance the flavor without overpowering the zucchini.

• Breadcrumbs (½ cup, optional) – For that irresistible crispy finish.

• Olive Oil or Melted Butter (2 tbsp) – Use this to grease the baking dish and toss with the breadcrumbs for a golden top.

Substitutions and Tips

• Zucchini Alternatives – Yellow squash works beautifully if you don’t have zucchini on hand.

• Cheese Swaps – Try Gruyère for a nuttier flavor, mozzarella for extra gooeyness, or pepper jack for a little heat.

• Milk Options – Unsweetened almond or oat milk can be used if you’re avoiding dairy.

• No Breadcrumbs? – Crushed crackers or even a sprinkle of extra Parmesan can give you that same crunchy top.

• Want to Make it a Meal? – Stir in cooked sausage, chopped ham, or leftover rotisserie chicken to make it heartier.

Best Cheese for Zucchini Casserole

Cheddar is the most commonly used cheese here, and for good reason. It melts beautifully and adds that classic casserole flavor. But you don’t have to stop there.

• Gruyère – Rich and nutty, perfect if you want to elevate the flavor.

• Mozzarella – For that dreamy, gooey melt.

• Parmesan – Best for adding a salty, crisp top layer.

• Pepper Jack – If you like a little spice, this one’s a fun twist.

For the best results, shred your own cheese. Pre-shredded cheese is coated with anti-caking agents that can affect melting and texture.

Kitchen Tools You’ll Need

No need to dig out any complicated gadgets. Just a few basics will get you from prep to plate.

Must-Have Tools

• 9×9-inch Baking Dish – This size gives you the perfect thickness and ensures even baking.

• Mixing Bowls – One large bowl for combining all your ingredients.

• Box Grater or Mandoline – For shredding or slicing the zucchini. A box grater works just fine.

• Colander or Clean Towel – You’ll need to drain and squeeze the zucchini to avoid a watery casserole.

Nice-to-Have Tools

• Garlic Press – Speeds things up if you don’t like mincing by hand.

• Food Processor – If you’re making a double batch or want to prep your ingredients in a flash.

• Silicone Spatula – Helps you mix without scratching your bowl and ensures nothing is left behind.

How to Make Zucchini Casserole

This is the part where the kitchen starts to smell amazing. The steps are easy to follow, and by the time you slide this dish into the oven, you’ll already be dreaming of that cheesy, golden topping. Let’s walk through it together, step-by-step.

Step 1: Preheat the Oven

Start by preheating your oven to 375°F (190°C). This gives the casserole enough heat to cook through evenly and develop a nice, golden crust on top.

While the oven heats up, grease a 9×9-inch baking dish with olive oil or melted butter. You can also use cooking spray, but butter adds that extra richness to the edges.

Step 2: Prep the Zucchini

If you’re using shredded zucchini, this step is important—don’t skip it. Zucchini is full of water, and that moisture can make your casserole soggy if you don’t drain it first.

• Place the shredded zucchini in a colander and sprinkle with a pinch of salt.

• Let it sit for about 10 minutes to draw out the liquid.

• Then, using your hands or a clean kitchen towel, squeeze out as much moisture as possible. You’ll be surprised how much comes out.

If you’re slicing the zucchini instead of shredding, you can skip the squeezing—but it still helps to pat the slices dry with a paper towel.

Step 3: Mix the Filling

In a large mixing bowl, combine the following:

• Your prepped zucchini

• Finely chopped onion

• Minced garlic

• Shredded cheddar cheese

• Grated Parmesan cheese

• Two large eggs

• Half a cup of milk

• Salt, pepper, and a pinch of paprika (if using)

Stir everything together until it’s well mixed. It might look a little loose at this stage, but it will set beautifully as it bakes.

Step 4: Assemble the Casserole

Pour the zucchini mixture into your prepared baking dish and spread it out evenly.

If you’re using breadcrumbs, now’s the time to mix them with a tablespoon of melted butter or olive oil. Sprinkle the mixture evenly over the top for a perfectly crispy finish.

No breadcrumbs? No problem. You can also top it with extra Parmesan or a mix of cheeses for a golden, bubbly crust.

Step 5: Bake

Place the dish in the center of your preheated oven and bake uncovered for 25 to 30 minutes. You’re looking for:

• A firm, set center (give it a gentle shake—if it wobbles too much, it needs more time)

• A golden-brown top that’s crisp but not overdone

If the top is browning too quickly, you can loosely cover it with foil for the last 10 minutes.

Step 6: Cool and Serve

Once it’s done, take the casserole out and let it cool for 5 to 10 minutes before slicing. This helps it firm up and makes serving much easier.

Top it with freshly chopped parsley or chives for a pop of color and freshness. Serve it warm and enjoy every bite.

Tips for Success

A few simple tips can take your casserole from good to incredible:

• Drain the zucchini thoroughly. This is the #1 tip to prevent sogginess.

• Use freshly grated cheese if possible. Pre-shredded cheese has additives that can affect texture.

• Don’t overbake. Keep an eye on the top. Once it’s golden and the center is set, it’s ready.

• Let it rest. Giving it a few minutes after baking allows everything to settle and slice cleanly.

How to Store Zucchini Casserole

One of the best things about this recipe? It keeps well, making it ideal for meal prep or leftovers.

At Room Temperature

• Once baked, the casserole can sit out for up to 2 hours.

• After that, move it to the fridge to keep it safe and fresh.

In the Refrigerator

• Store leftovers in an airtight container or cover the baking dish with foil or plastic wrap.

• It’ll keep in the fridge for 3 to 4 days.

• Reheat slices in the microwave or warm in the oven at 350°F until heated through.

Freezing Tips

Yes, you can freeze zucchini casserole—just keep a few things in mind:

• Let it cool completely before freezing.

• Wrap tightly in plastic wrap, then foil, or store in a freezer-safe container.

• Freeze for up to 2 months.

• To reheat, thaw overnight in the fridge, then warm in a 350°F oven covered with foil until hot in the center.

Frequently Asked Questions (FAQs)

Can I make zucchini casserole ahead of time?

Absolutely. You can assemble the entire casserole, cover it tightly, and store it in the refrigerator for up to 24 hours before baking. When you’re ready, bake as directed. You may need to add a few extra minutes if it goes straight from the fridge to the oven.

Can I freeze zucchini casserole?

Yes, this casserole freezes quite well. Bake it first, let it cool completely, then freeze. Just know that the texture might be slightly softer after freezing, but the flavor holds up beautifully.

How do I keep my casserole from getting watery?

The trick is in the zucchini. Be sure to salt, drain, and squeeze it thoroughly before mixing it into the casserole. This step helps remove excess moisture and keeps the texture just right.

Can I use yellow squash instead?

You sure can. Yellow squash has a similar texture and moisture content, so it works as a perfect substitute for zucchini in this recipe.

Related Recipes

If you loved this zucchini casserole, you might enjoy these comforting dishes too:

• Creamy Mushroom and Asparagus Chicken Penne: Rich, creamy, and perfect for weeknights.

• Spinach and Cheese Casserole: A vegetarian favorite with layers of cheese and leafy greens.

• Cheesy Rotini with Garlic Butter Beef: Pasta meets savory beef in this satisfying dish.

• The Ultimate Cowboy Casserole: Hearty and loaded with meat, veggies, and cheese.

• Creamy Garlic Chicken Penne: Easy, flavorful, and full of comforting garlic and cheese goodness.

Conclusion

Whether you’re making the most of summer zucchini or just craving something warm and cheesy, this zucchini casserole hits all the right notes. It’s easy to make, endlessly customizable, and always satisfying.

Make it once, and it’ll earn a regular spot in your rotation. And don’t be surprised if someone asks for the recipe.

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