This zucchini and summer squash casserole has yellow and green squash layered into a spiral, topped with breadcrumbs and a little cheese, making it summer in a baking dish. It’s light, it’s colorful, and it comes together in about 30 minutes. It holds its own on a weeknight dinner table just as easily as it does at Thanksgiving.
Every summer, my garden turns into a squash situation. You know how that goes: you plant two plants, and suddenly you have more zucchini than you know what to do with. This casserole is one of my tried-and-true favorites because it uses a lot of squash, looks impressive, and my family actually eats it (which, obviously, is the only bar that really matters).
What makes this one different from your typical squash casserole is what’s not in it. There is no cream of mushroom soup, no stick of butter, and no heavy, dense filling that sits in your stomach for three hours. Just the vegetables, a light layer of seasoned breadcrumbs, and enough cheese to make it feel like a treat without going overboard. The squash gets tender in the center while the top turns golden.
Reader Review
I will be making this as a side dish for Thanksgiving, thank you kindly for sharing! Grateful holiday wishes! Gobble, Gobble!
— Gatsby
If you’ve ever thought squash casserole sounds boring or too heavy, this one will change your mind. It works as a summer side when produce is cheap and plentiful, and it works just as well on a holiday table when you want something colorful next to the main dish.
Below, you’ll find everything you need, including slicing tips, the best way to layer for that spiral look, and a few easy swaps if you want to mix it up. Once you try this recipe, you’ll never look at that pile of summer squash the same way again.
Looking for more easy recipe ideas for summer squash? Try my recipes for zucchini pickles, air fryer yellow squash, or chocolate zucchini muffins.
Ingredient Notes
For exact amounts needed see the recipe card below
- Zucchini
- Yellow squash
- Olive oil
- Parmesan cheese
- Panko breadcrumbs: Regular breadcrumbs work too.
- Salt
- Pepper
How to Make Squash and Zucchini Casserole
- Preheat your oven to 350 degrees F.
- Wash and slice the zucchini and yellow squash into 1/4-inch-thick rounds. Try to keep your slices uniform, so they cook evenly. I use a sharp knife and take my time, but a mandoline slicer makes quick work of this if you have one.
- Arrange the squash slices in a 9-inch square baking dish or pie plate. If I use a pie plate, I arrange them in concentric circles, alternating between yellow and green slices for a pretty spiral pattern. For a square dish, layer them in rows.
- Drizzle the olive oil over the arranged squash, then sprinkle with Parmesan cheese and breadcrumbs. Finish with a generous sprinkle of salt and black pepper.
- Bake uncovered for 25 minutes until the top is lightly browned and the squash is tender. It’s done when you can easily pierce the squash with a fork, and the breadcrumbs have turned golden brown. If the top isn’t as brown as you’d like after 25 minutes, pop it under the broiler for a minute or two, but watch it carefully so it doesn’t burn.
Serving Ideas
This casserole fits into almost any meal plan, which is exactly why I love it. I make it constantly during summer when my garden explodes with squash, and I can’t give it away fast enough.
Serve it as a side dish alongside grilled chicken or fish. The mild flavor of the roasted squash pairs beautifully with just about any protein. I often pair it with smoked chicken or simple grilled salmon, and my family never complains.
It also works as a light main course if you’re looking for something vegetarian. For potluck season, this casserole is amazing. It travels well, reheats beautifully, and looks impressive when you set it down on the table. Nobody needs to know how easy it is to make.
How to Store
Leftovers can be kept in an airtight container in the refrigerator for 2-3 days. The breadcrumb topping will soften a bit as it sits. Reheat your leftovers either in the microwave for a quick warm-up or in a 350-degree oven for about 10 minutes to restore some crispness to the panko topping.
Tips & Tricks
Be sure to check out the step by step instructions
- When you’re cutting your squash and zucchini, aim for a thickness of ¼ inch. Too thick and you’ll end up with undercooked vegetables in the middle. Too thin and they’ll turn to mush. If you’ve got a mandoline slicer gathering dust in your cabinet, it’s time to let it shine. Just watch your fingers.
- If you are arranging in a spiral, start at the outer edge and work inward, overlapping each slice slightly.
- To make ahead, slice the vegetables and arrange them in the dish. Then store them in the refrigerator until you are ready to bake. Add the oil, breadcrumbs, and cheese right before baking.
- Parmesan is classic, but you can use different cheeses, like cheddar or Romano. Just keep the total amount at ⅓ cup.
- You can mix up the type of summer squash in the casserole, or use all yellow squash or all zucchini.
- If you’re avoiding breadcrumbs or don’t have any on hand, you can use crushed crackers, crushed cornflakes, or finely chopped nuts like almonds or pecans. Each will give you a different flavor and texture, but all work well. You could also double the cheese and skip the breadcrumbs entirely for a lower-carb option.
Reader Questions
The main difference between these two vegetables is their color. Zucchini is green and yellow squash is, obviously, yellow. The shapes vary sometimes too, yellow squash can be similar in shape to zucchini or have a wide bottom that tapers to a smaller top.
This usually happens for one of two reasons. First, your squash might have been cut too thin, or your oven temperature might have been too low, causing the vegetables to steam rather than roast. Second, you might have used particularly watery vegetables. Next time, try slicing them a bit thicker or increasing the oven temperature to 375°F to help evaporate more moisture.
Yes, but you’ll need to use a 9×13-inch baking dish instead of a 9-inch square dish. The cooking time might increase by 5-10 minutes since you’ll have more vegetables to cook through. Just keep an eye on it and test for tenderness.
If you notice the breadcrumbs browning too quickly, loosely cover the casserole with aluminum foil for the rest of the cooking time. You can also try placing the baking dish on a lower oven rack, which puts it further from the heating element.
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Squash and Zucchini Casserole Recipe
Ingredients
- 1 – 2 medium zucchini
- 1 – 2 yellow squash
- 3 tablespoons olive oil
- ⅓ cup grated Parmesan cheese
- ⅓ cup panko crumbs
- salt & pepper to taste
Instructions
- Preheat the oven to 350 degrees F.
- Wash the zucchini and yellow squash and slice both into 1/4 inch thick slices.1 – 2 medium zucchini, 1 – 2 yellow squash
- Arrange the squash slices in concentric circles in a 9inch square baking dish or a pie plate, alternating yellow and green.
- Drizzle the squash mixture with the olive oil, then sprinkle with cheese and bread crumbs. Sprinkle salt and black pepper on top of the casserole.3 tablespoons olive oil, ⅓ cup grated Parmesan cheese, ⅓ cup panko crumbs, salt & pepper to taste
- Bake in the preheated oven uncovered for 25 minutes until the top is lightly browned.
Notes
- When you’re cutting your squash and zucchini, aim for a thickness of ¼ inch. Too thick and you’ll end up with undercooked vegetables in the middle. Too thin and they’ll turn to mush.
- If you are arranging in a spiral, start at the outer edge and work inward, overlapping each slice slightly.
- To make ahead, slice the vegetables and arrange them in the dish. Then store them in the refrigerator until you are ready to bake. Add the oil, breadcrumbs, and cheese right before baking.
- Parmesan is classic, but you can use different cheeses, like cheddar or Romano. Just keep the total amount at ⅓ cup.
- You can mix up the type of summer squash in the casserole, or use all yellow squash or all zucchini.
- If you’re avoiding breadcrumbs or don’t have any on hand, you can use crushed crackers, crushed cornflakes, or finely chopped nuts like almonds or pecans. Each will give you a different flavor and texture, but all work well. You could also double the cheese and skip the breadcrumbs entirely for a lower-carb option.
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Nutrition Information
Nutrition facts are estimates.
Squash recipe sounds good for Thanksgiving
I WILL BE MAKING THIS AS A SIDE DISH FOR THANKSGIVING , THANK YOU KINDLY FOR SHARING !!! GRATEFUL HOLIDAY WISHES !!! GOBBLE ,GOBBLE !!! “GATSBY”