Easy Cheesy Zucchini Casserole

Cheesy Zucchini Casserole saved my sanity last August when zucchini literally took over my kitchen counter. My neighbor dropped off this massive bag, and I was staring at enough squash to feed a small army. My grandma always said never waste good food, so I called her up for advice.

She laughed and said, “Honey, throw it all in a casserole with some cheese and mayo – trust me on this one.” I thought she’d lost her mind, but that woman knew what she was talking about. Three zucchini later, I had this bubbling, golden masterpiece that disappeared faster than I could blink.

❤️ Why You’ll Love This Recipe

Listen, I’ve tried every zucchini recipe under the sun, and this one hits different. It’s got that perfect balance where you actually taste the zucchini but it’s not screaming “I’m a vegetable!” at your kids. The cheese gets all melty and forms this gorgeous golden crust that makes you forget you’re eating something healthy. My husband went back for thirds the first time I made it, and he usually runs when he sees green vegetables on his plate.

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📝 Ingredient List

For the Casserole:

• 3 cups zucchini, cut into pieces
• 2 large eggs
• 1/2 cup mayonnaise
• 1 1/2 cups shredded cheddar cheese, divided
• 1/2 teaspoon garlic powder
• 1/4 teaspoon black pepper
• Additional cheddar cheese for topping

Substitution Notes:

• Mayo substitute: Greek yogurt works beautifully for a lighter version
• Cheese options: Try Monterey Jack or a sharp white cheddar for different flavor profiles
• Add-ins: Cooked bacon bits or caramelized onions make delicious additions

🔍 Why These Ingredients Work

Okay, here’s where Grandma’s wisdom really shines. She told me to parboil the zucchini first because nobody wants soggy, mushy vegetables floating in liquid. Those three minutes of boiling soften them just enough without turning them into baby food. The mayo sounds weird, I know, but it’s pure genius – it makes everything creamy without being heavy like cream would be. Eggs hold everything together like glue, and that cheddar cheese? Well, cheese makes everything better, period. The garlic powder and pepper just wake everything up without being fancy about it.

Essential Tools and Equipment

• Large pot for parboiling zucchini
• Colander for draining
• Mixing bowl
• 1½-quart casserole dish
• Aluminum foil
• Sharp knife and cutting board

👩🍳 How to Make Cheesy Zucchini Casserole

Step 1: Get That Zucchini Ready Chop your zucchini into chunks about the size of a dice. Don’t stress about perfect pieces – rustic works just fine here. Boil a big pot of water and dump them in for exactly 3 minutes. Set a timer because 4 minutes turns them to mush, and nobody’s got time for that. Drain them really well and let them sit while you get everything else ready.

Step 2: Heat Things Up Crank your oven to 350°F and grease that casserole dish like your life depends on it. I use butter, but cooking spray works too.

Step 3: Mix It All Together Crack those eggs into a bowl and whisk them with the mayo until it’s smooth. Toss in most of your cheese (save some for the top because we’re not animals), the garlic powder, and pepper. Mix it all up and then fold in your drained zucchini. Don’t be gentle – really get it all coated.

Step 4: Bake It Perfect Dump everything into your dish and spread it around. Sprinkle the rest of that cheese on top like you mean it. Cover with foil and stick it in the oven for 30 minutes. Then pull off that foil and let it go another 30 minutes until the top looks golden and gorgeous.

And if you’re looking for more zucchini recipes, check out my Keto Crustless Zucchini Quiche Or Keto Chicken Parmesan Zucchini Boats – they’re both reader favorites!

Tips from Well-Known Chefs:

Ina Garten’s Wisdom: “The key to any great casserole is proper drainage – never skip the step of letting your vegetables release their moisture first.”

Julia Child’s Secret: “Taste as you go and adjust seasoning. Every zucchini is different, and your palate knows best.”

❗ You Must Know

The Drainage Rule: This is absolutely critical – after parboiling your zucchini, let it drain for at least 5 minutes. Press gently with paper towels if needed. Watery zucchini equals a soggy casserole, and nobody wants that!

Personal Secret: I always add an extra handful of cheese to the top during the last 10 minutes of baking. It creates this gorgeous golden crust that makes the presentation absolutely stunning.

💡 Pro Tips & Cooking Hacks

Moisture Control Hack: If your zucchini seems extra watery, sprinkle the pieces with salt after cutting and let them sit for 15 minutes before parboiling. This draws out even more moisture.

Make-it-Special Tip: Try mixing in 2 tablespoons of fresh herbs like chives or parsley for a pop of color and fresh flavor.

Avoid This Mistake: Don’t overbake the first covered portion – you want the zucchini tender, not mushy.

Smart Shortcut: You can parboil your zucchini up to a day ahead and store it in the fridge until you’re ready to assemble.

🎨 Flavor Variations / Suggestions

My sister throws in leftover bacon from breakfast and uses pepper jack cheese – now her kids actually fight over who gets the last scoop. Last week I tried it with some sun-dried tomatoes I had sitting around, and wow, it tasted like something from a fancy restaurant. My neighbor swears by adding diced bell peppers, but honestly, I think that’s just showing off. If you’re feeling brave, toss in some red pepper flakes, but don’t blame me when your mouth’s on fire.

⏲️ Make-Ahead Options

Sunday meal prep just got easier, friends! I make this whole thing Saturday night and stick it in the fridge. Next day, just pop it in the oven straight from the cold – give it maybe 10 extra minutes since it’s chilly. My mom actually freezes hers before baking, but she’s got more freezer space than I do. Just wrap it tight and it’ll keep for months. I tried freezing it after baking once, and it was fine but not as good as fresh.

Recipe Notes & Baker’s Tips

Look, I’ve messed this up enough times to know what works and what doesn’t. If your zucchini chunks are bigger, just boil them a minute longer – no big deal. Sometimes mine looks a little wobbly in the middle when I pull it out, but it firms up as it cools, so don’t panic. I learned the hard way that putting it on the top rack makes the cheese burn while the bottom stays raw. Middle rack is your friend here. Oh, and if you’re one of those people who cuts perfect little cubes, more power to you, but rough chops work just fine.

🍽️ Serving Suggestions

This goes with pretty much everything, but I love it next to grilled chicken or pork chops. My husband eats it with his Sunday pot roast like it’s mashed potatoes or something. Sometimes I just make a big salad and call this dinner – don’t judge me, we’ve all been there. The kids eat it for breakfast with scrambled eggs, which sounds weird but actually works. Last week I brought it to a potluck and it disappeared before the main dish even showed up.

I hope this becomes a new go-to in your kitchen, especially during zucchini season! There’s something so satisfying about turning garden abundance into something this delicious and comforting.

🧊 How to Store Your Easy Cheesy Zucchini Casserole

Leftovers live in my fridge for about 4 days, and honestly they taste better the next day. I just cover it with foil and stick it back in the oven at 325 for maybe 20 minutes. My lazy days, I just microwave a chunk for like a minute and call it good. I tried freezing pieces once and they were okay, but fresh is definitely better. If you’re gonna freeze it, just thaw it overnight and heat it up slow so it doesn’t get all weird and separated.

⚠️ Allergy Information

My daughter’s lactose intolerant, so I’ve made this with those fake cheese shreds and vegan mayo – worked fine, just not as gooey. For the egg thing, I honestly have no clue what to substitute there. Maybe those flax egg things people talk about? I’ve never tried it myself. If you’re dealing with food allergies, you probably know way more about substitutions than I do anyway.

❓ Questions I Get Asked

Q: Can I use frozen zucchini for this casserole? A: I tried it once when I was desperate, and it was okay but super watery. If that’s all you got, thaw it completely and squeeze the heck out of it with paper towels first.

Q: Why is my zucchini casserole watery? A: Because you didn’t drain your zucchini long enough! I learned this the hard way. Leave it there for a nice 5 minutes and press it gently with your hands.

Q: Can I make this casserole in advance? A: Yeah, I’ve always got one of those going. You can make it the night before and shove it in the fridge. Just bake it a little longer since it’s cold.

Q: What can replace mayonnaise? A: Yes I’ve used Greek yogurt but it’s not quite as creamy. My friend swears by sour cream, but I’ve yet to try that.

Q: How do I tell when the casserole is done? A: Shove a knife into the center — if it comes out mostly clean and the top is golden, you’re good to go. Don’t overthink it.

💬 Tried this recipe? Leave a comment and rating below! I’d love to hear about your favorite variations or any creative add-ins you discovered. Share your photos and tag me – seeing your kitchen successes absolutely makes my day!