Air Fryer Zucchini Onion Pie (Crustless Bisquick Pie)

Air Fryer Zucchini Onion Pie is a crustless, quiche-style pie made with diced zucchini, onion, Bisquick, eggs, and parmesan — cooked in a 7-inch pan right in your air fryer basket. It slices clean, holds together, and uses up a lot of summer squash in one dish.

This is the air fryer version of the classic Bisquick zucchini pie. The oven version takes 35 to 45 minutes and heats up your whole kitchen in August, which is exactly when zucchini is coming in fastest. The air fryer does it in about 30 to 35 minutes without turning the house into a sauna.

One thing worth saying up front, because it is the part most recipes skip: pan size matters more than anything else here. Get that right and this recipe is nearly foolproof. Get it wrong and you end up with a wet center. There is a full section on it below.

Why This Recipe Works

• It is crustless. No dough, no rolling, no blind baking. The Bisquick sinks slightly and forms its own soft base as it cooks.
• It slices. Three eggs plus a cup of baking mix give it enough structure to cut into wedges rather than scooping it like a casserole.
• It uses a real amount of zucchini. Three cups per pie, which is roughly two medium zucchini.
• It reheats well. Better on day two, honestly. The flavors settle.

A note on fat, since air fryer recipes often oversell this: this is a rich pie. It uses a half cup of oil, the same as the traditional oven version, because that oil is what keeps the crumb tender instead of dry and eggy. The air fryer saves you time and oven heat here — not calories. You can pull the oil back to a third of a cup if you want, and it still works, just with a slightly firmer texture.

Ingredients

• Zucchini: About two medium zucchini. Small, firm ones have less water than the giant end-of-season baseball bats. If yours are large and seedy, scoop the spongy center out first.
• Onion: Yellow or sweet. It softens and sweetens as the pie cooks.
• Minced garlic: Or use garlic powder.
• Eggs: The binder. This is what makes it sliceable rather than crumbly.
• Bisquick: Or any all-purpose baking mix. Homemade instructions are below.
• Parmesan cheese: Grate it yourself if you can. Pre-shredded parmesan has anti-caking starch that makes the texture slightly grainy.
• Vegetable oil: Or canola, avocado, or any neutral oil.
• Dried parsley: Or swap in fresh.
• Salt and black pepper: The salt is not optional. Parmesan is salty but not salty enough to carry a cup of baking mix on its own.

What Pan Fits in an Air Fryer?

This is where most people go wrong when they adapt an oven recipe.

The traditional recipe calls for a 9-inch deep-dish pie plate. That will not fit in most air fryer baskets. If you force it into a large oven-style air fryer, the batter sits shallow and wide, and the cook time changes completely.

Use a 7-inch round cake pan or a 7-inch springform pan, at least 2 inches deep. That is the standard accessory size for a 5.8-quart basket air fryer and it holds this batter at roughly the depth it was designed for.

Other options that work:

• 7-inch round cake barrel (the tall bucket-style accessory) — great fit, may need 3 to 5 extra minutes because it is deeper
• 6-inch pan — works, but the batter sits deeper, so add 5 to 8 minutes and check the center carefully
• 8-inch pan in a large oven-style air fryer — works, batter is shallower, check at 22 minutes

If your pan is not listed here, measure the inside of your basket and pick the largest round pan that leaves about a half inch of clearance on all sides for air to move. Airflow is the whole point of an air fryer, and a pan that touches the walls will cook unevenly. My air fryer cooking charts and tips cover accessory sizing across different models.

How to Make Air Fryer Zucchini Onion Pie

Step 1: Prep the pan. Grease a 7-inch round pan well with cooking spray or oil, including the sides. This batter sticks.

Step 2: Whisk the wet ingredients. In a large bowl, whisk the 3 eggs, 1/2 cup oil, garlic, parsley, salt, and pepper until fully combined and slightly frothy. Do this before anything else goes in — once the vegetables are added you cannot get the egg evenly distributed anymore.

Step 3: Add the Bisquick and cheese. Stir in 1 cup Bisquick and 1 cup grated parmesan. Mix just until no dry flour is visible. A few small lumps are fine. Overmixing makes it tough.

Step 4: Fold in the vegetables. Add 3 cups diced zucchini and 1/4 cup diced onion. Fold gently until every piece is coated in batter. The mixture will look thick and barely wet — that is correct. The zucchini releases moisture as it cooks.

Step 5: Fill the pan. Pour into the greased pan and smooth the top flat with a spatula. An even surface cooks evenly.

Step 6: Air fry at 320°F for 30 to 35 minutes. Start checking at 25 minutes. If the top is browning faster than the center is setting, tent a piece of foil loosely over the pan for the last 10 minutes.

Step 7: Test the center. Insert a toothpick or thin knife into the middle. It should come out clean or with a few moist crumbs — not wet batter. If it is wet, give it another 5 minutes and test again. This is the step that determines whether the recipe works.

Step 8: Rest before slicing. Let it sit 10 minutes in the pan. It firms up considerably as it cools, and slicing it hot will give you a mess. Run a knife around the edge, then slice into wedges.

How to Tell When It Is Done

• The top is golden and set, not glossy or jiggly
• The edges have pulled slightly away from the pan
• A toothpick in the center comes out clean
• The center springs back lightly when pressed

If your air fryer runs cool, or you are using a deeper pan, this can take up to 40 minutes. Trust the toothpick over the timer.

What Is Bisquick, and How Do I Make It?

Bisquick is a shelf-stable baking mix made from flour, shortening, baking powder, and salt. It is sold in most American grocery stores, but it is not available everywhere — so here is how to make your own.

Homemade baking mix (makes about 7 cups):

• 6 cups all-purpose flour
• 3 tablespoons baking powder
• 1 tablespoon salt
• 1 cup vegetable shortening

Pulse everything in a food processor until it looks like coarse crumbs. Store in an airtight container in the pantry for up to 3 months, or in the freezer for longer. Use it cup for cup in place of Bisquick.

Making just enough for this recipe? Combine 1 cup flour, 1 1/2 teaspoons baking powder, 1/2 teaspoon salt, and 2 1/2 tablespoons shortening. Cut the shortening in with a fork until crumbly. If you use this version, reduce the added salt in the pie to 1/4 teaspoon.

Is It a Pie, a Quiche, or a Casserole?

Somewhere between all three, which is why you will see it called all three online. There is no crust, so it is not a pie in the traditional sense. It has a strong egg custard element like a quiche, but the baking mix gives it more lift and a softer, cake-like crumb. If you want something closer to a true casserole — looser, cheesier, scoopable rather than sliceable — my air fryer zucchini casserole goes in that direction.

Variations

• Layer instead of dice. Thinly slice the zucchini and onion on a mandoline and arrange them in layers, pouring batter between each. Slower to assemble, prettier to serve.
• Change the cheese. Sharp cheddar makes it richer, mozzarella makes it stretchier, pepper jack adds heat. Swap up to half the parmesan.
• Add meat. A half cup of cooked crumbled sausage or chopped bacon turns this into a main dish. Cook and drain it fully first.
• Add herbs. A teaspoon of dried basil, oregano, or thyme all work. Fresh basil goes in at the end.
• Half zucchini, half yellow squash. Same volume, better color contrast.

What to Serve With It

It works as a vegetarian main, a brunch dish, or a side next to grilled steak, chicken, or a pot of chili. If you are building a summer spread, air fryer parmesan zucchini foil packets round it out on the vegetable side, and air fryer sun-dried tomatoes are worth having on hand to scatter over the top.

How to Store and Reheat

Refrigerator: Cover tightly and refrigerate up to 4 days. It slices more cleanly cold than warm.

Freezer: Wrap individual slices in plastic, then foil, and freeze up to 3 months. Thaw overnight in the refrigerator before reheating.

Reheating: Air fry at 320°F for 4 to 6 minutes, or until warmed through. This is genuinely better than the microwave, which turns the edges rubbery. From frozen, add about 4 minutes.

Make ahead: You can mix the batter and refrigerate it in the pan, covered, for up to 12 hours before cooking. Add 3 to 5 minutes to the cook time since you are starting cold.

Frequently Asked Questions

Why is my zucchini pie watery in the middle? Almost always underbaking, not the zucchini. Test with a toothpick rather than going by the timer — different air fryers and pan depths vary a lot. If the toothpick comes out wet, it needs more time. A too-large, too-shallow pan can also cause the edges to set while the middle lags.

Do I need to salt and drain the zucchini first? No. The batter is thick enough to absorb the moisture the zucchini releases. If you are using very large, watery zucchini, scoop out the seedy center before dicing.

Can I use frozen zucchini? Yes. Thaw it and squeeze out as much liquid as you can in a clean towel first. The texture will be softer than fresh, which is fine in a soft-set pie like this. Do not use frozen for recipes where you want crispness.

Can I bake this in the oven instead? Yes. Use a greased 9-inch deep-dish pie plate and bake at 350°F for 35 to 45 minutes, until golden and set in the center.

Can I make it dairy free? The parmesan is doing a lot of the flavor work here, so a swap will change the result noticeably. A firm dairy-free parmesan-style cheese is the closest option; increase the salt slightly if you use one that is mild.

Can I reduce the oil? Down to 1/3 cup with good results. Below that the crumb gets dry and eggy.

More Air Fryer Zucchini Recipes

If this one worked for you, these use the same summer glut:

• Air Fryer Zucchini Cheddar Savory Muffins — same idea, portioned individually
• Air Fryer Zucchini Bacon Cheddar Scones
• Air Fryer Zucchini Pizza Boats
• Air Fryer Zucchini Pizza Bites
• Air Fryer Zucchini Burgers

For everything else, my full air fryer recipe collection is the place to browse.