Air Fryer Zucchini Casserole (Easy & Cheesy)

This Air Fryer Zucchini Casserole is everything a summer side dish should be — tender chunks of fresh zucchini and sweet onion, folded into a cheesy, savory batter and baked until the top turns golden and the edges get just a little crisp. It comes together in one bowl, cooks in about 15 minutes, and tastes like something that took far more effort than it actually did.

This is a recipe my mother made when we were kids, back when it went into the oven for close to an hour. Moving it to the air fryer changed everything: the circulating heat sets the eggs and browns the cheese in a fraction of the time, and I’m not heating up the whole kitchen in the middle of July. One bite of that golden, cheesy top and my family started requesting it weekly — it’s now the dish I make when someone asks, “can you bring that zucchini thing?”

If your garden or farmers market haul is piling up, this casserole is the answer. Once zucchini season hits, I rotate it with my crispy Air Fryer Zucchini Chips and a loaf of Air Fryer Chocolate Chip Zucchini Bread, and somehow we still never run out of zucchini.ck Zucchini, Blackstone Griddle Zucchini, or Ninja Woodfire Grilled Zucchini.

Why You’ll Love This Recipe

• Fast. About 20 minutes of prep and 15 minutes in the air fryer — no waiting on the oven to preheat.
• Simple ingredients. Fresh zucchini, onion, eggs, cheese, and pantry staples. Nothing fancy.
• Family-friendly. The cheesy, savory bake wins over even the zucchini skeptics at my table.
• Flexible. Works as a side dish, a vegetarian main, or a base you can bulk up with cooked ground beef.

Ingredients

• Zucchini — about 3 cups chopped (roughly 3 small zucchini). Fresh works best here; frozen releases too much water.
• Onion — chopped, for savory depth.
• Eggs — bind everything together.
• Bisquick (or baking mix) — gives the casserole structure. A gluten-free baking mix works too.
• Vegetable oil — keeps the bake moist.
• Shredded cheese — I use a cheddar blend, but Parmesan or mozzarella are great.
• Seasonings — salt, black pepper, dried parsley, and oregano.

The full quantities and step-by-step directions are in the printable recipe card at the bottom of this post.

How to Make Air Fryer Zucchini Casserole

Step One: Chop the zucchini into small pieces until you have about 3 cups, then chop the onion. Add both to a large bowl with the salt, pepper, parsley, and oregano, and mix well.

Step Two: Stir in the eggs, oil, Bisquick, and shredded cheese until everything is evenly combined.

Step Three: Pour the mixture into a greased baking dish that fits inside your air fryer. Set the temperature to 320 degrees F and the cook time for 15 minutes.

Step Four: Check the casserole at the 15-minute mark. The top should be golden and the center set. If it needs a few more minutes, add them in small increments. Let it cool slightly before slicing and serving.

Oven Method (No Air Fryer? No Problem)

Several readers have asked how to make this without an air fryer — and the good news is it works beautifully in a conventional oven. Preheat to 350°F. Spoon the mixture into a greased 8×8 baking dish and bake for 30 to 35 minutes, until the top is golden and a knife inserted in the center comes out clean. It’s an easy way to share this with anyone who doesn’t own an air fryer (hi, sis).

Pro Tips

• Use an oven-safe dish that fits your basket. Ceramic, metal, or silicone all work — just leave room around the edges for air to circulate.
• Don’t skip the check. Air fryers vary, so peek at 15 minutes and judge by color and set, not the clock alone.
• Pat the zucchini dry. Blotting the chopped zucchini with a paper towel keeps the casserole from turning watery.
• Make it a main dish. Stir in a cup of cooked, drained ground beef or sausage before baking.

What to Serve With Air Fryer Zucchini Casserole

This casserole is a natural side for simple proteins. On busy weeknights I pair it with my Air Fryer Butterflied Chicken Breast — the chicken and the casserole cook at similar temperatures, so dinner comes together fast. It’s also excellent alongside Air Fryer Salmon for a lighter meal, or with Air Fryer Pork Tenderloin when I want something heartier. And if you forgot to thaw dinner (we’ve all been there), my Frozen Pork Chops in the Air Fryer go straight from freezer to table right next to this casserole.

For a vegetarian meal, serve it with a fresh green salad or over rice or quinoa.

Storing and Reheating

Refrigerator: Let the casserole cool completely, then store it tightly covered in the fridge for 3 to 4 days.

Freezer: Wrap individual portions well and freeze for up to 2 months. Thaw overnight in the refrigerator before reheating.

Reheating: For the best texture, reheat portions in the air fryer at 350 degrees F for 4 to 5 minutes, until warmed through the center. The microwave works in a pinch (1 to 2 minutes), though the top won’t re-crisp.

Make ahead: You can assemble the casserole, cover it, and refrigerate it up to a day in advance — just add a couple of minutes to the cook time if it goes in cold.

Air Fryer Zucchini Casserole Recipe FAQs

Can I use frozen zucchini? Fresh zucchini gives the best texture. Frozen zucchini releases a lot of water as it cooks, which can make the casserole soggy.

Can I substitute the eggs? Yes — a flaxseed or chia “egg” works well for binding if you need an egg-free version.

How can I make it gluten-free? Swap the Bisquick for a gluten-free baking mix, cup for cup. Everything else in the recipe is naturally gluten-free.

How can I make it spicier? Add red pepper flakes, chopped jalapeños, or a dash of hot sauce to the mixture before baking.

More Air Fryer Zucchini Recipes

If your garden is still producing faster than you can cook, try my crispy Keto Air Fryer Zucchini Fries with garlic aioli, these fun Air Fryer Zucchini Pizza Bites the kids love, or my no-breading Crispy Air Fryer Zucchini Slices — the salt-and-drain trick in that one fixes soggy zucchini for good.

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