Easy Yellow Squash Casserole Recipe

There’s something nostalgic about the warm, comforting aroma of squash casserole baking in the oven. The tender yellow squash, creamy filling, and crispy golden topping make it a Southern-style classic that never goes out of style.

I first made this dish one summer when our garden was overflowing with yellow squash. I wanted something simple, cozy, and a little indulgent—and this casserole checked every box. Since then, it’s been a go-to for everything from weeknight dinners to holiday potlucks.

Let’s dive into what makes this humble casserole a standout.

Why You'll Love This Easy Yellow Squash Casserole

Get ready to fall in love with a dish that’s as comforting as it is easy to make. This yellow squash casserole has quickly become a favorite in our kitchen, and I’m betting it’ll earn a permanent spot in yours, too.

First, it’s truly simple and fuss-free. With just a handful of pantry staples and some fresh squash, you can have this casserole prepped and in the oven in under 20 minutes. No fancy steps or complicated ingredients here.

It’s also budget-friendly, especially in the summer when yellow squash is in season and often overflowing at farmers' markets or in backyard gardens. You don’t need anything pricey to make something that tastes rich and satisfying.

Another big bonus? It’s crowd-pleasing and kid-approved. Even the picky eaters in my house go back for seconds, thanks to the cheesy, creamy filling and crunchy topping that makes vegetables feel like comfort food.

And finally, it’s incredibly versatile. Serve it as a cozy side with grilled chicken or pork chops, or enjoy it as a light vegetarian main dish alongside a crisp green salad.

Whether you’re cooking for your family or feeding a crowd, this casserole brings old-school comfort with modern-day ease.

Ingredients Notes

The beauty of this dish lies in its short, simple ingredient list. Each component has a job to do, and together they create a warm, creamy casserole with the perfect mix of soft and crisp textures.

Yellow squash is, of course, the star. Choose small to medium squash with bright skin and no blemishes—they’re more tender and have better flavor than oversized ones. You’ll want to slice them thin so they cook down quickly and blend into the creamy base.

Onion adds a mild savory note that balances the sweetness of the squash. I like to use a yellow or sweet onion, diced small so it softens quickly in the pan and melts into the background without overpowering the other flavors.

Eggs and sour cream work together to form the base of the filling. The eggs provide structure, while the sour cream gives the casserole its signature creaminess and slight tang. If you don’t have sour cream on hand, Greek yogurt is a great swap.

Cheddar cheese brings everything together with a sharp, melty richness. I recommend shredding your own from a block for best melt and flavor. A mild or medium cheddar works beautifully, but if you like a bolder flavor, try sharp cheddar or even a blend.

For that irresistible crispy topping, crushed buttery crackers like Ritz are my go-to. Tossed with a little melted butter, they form a golden crust that contrasts beautifully with the soft squash underneath.

No special tools required—just a large skillet for sautéing and a casserole dish for baking. A mandoline can help speed up slicing the squash, but a good sharp knife works just fine.

How To Make This Easy Yellow Squash Casserole

Making this casserole is as easy as it gets. From slicing the squash to pulling the bubbling dish out of the oven, you’re only a few simple steps away from comfort food heaven.

Start by prepping your squash. Wash it well, trim off the ends, and slice it into thin rounds—about ¼ inch thick. This ensures the squash softens nicely without turning to mush. Then, sauté it with the chopped onion in a bit of butter or olive oil until everything is just tender and starting to release some of its moisture.

While the squash is cooking down, preheat your oven and mix up the creamy filling. In a large bowl, whisk together the eggs, sour cream, and a handful of shredded cheddar cheese. Once the squash mixture has cooled slightly, stir it into the bowl, making sure everything is well combined.

Pour the squash mixture into a greased baking dish and smooth it out evenly. Then it’s time for the best part—the topping. Crush your buttery crackers and toss them with melted butter until they’re lightly coated. Sprinkle the mixture over the casserole in an even layer.

Bake the casserole until the edges are bubbling and the top is golden brown, usually about 25–30 minutes. You’ll know it’s ready when the center is set and the aroma starts drawing people into the kitchen.

From start to finish, you’re looking at about 45 minutes total. It’s just the right amount of time to get the rest of dinner ready—or sneak in a little break before it’s time to eat.

Storage Options

Leftovers? You’re in luck—this casserole keeps really well. Once it’s cooled, cover the dish tightly with foil or transfer portions to airtight containers. It’ll stay fresh in the fridge for up to 4 days.

If you want to freeze it, you absolutely can. Assemble the casserole and stop before adding the topping. Wrap it tightly and freeze for up to 2 months. When you’re ready to bake, thaw it in the fridge overnight, add the cracker topping, and bake as usual.

For reheating, the oven is your best bet. Cover loosely with foil and bake at 350°F for 15–20 minutes, or until heated through. You can also microwave individual servings, though the topping won’t stay quite as crispy.

It’s a great make-ahead option, especially during the holidays or for meal prepping your week.

Variations and Substitutions

One of the best things about this yellow squash casserole is how easy it is to adapt. Whether you’re trying to use what you have or suit different dietary needs, there’s plenty of room to play.

If you don’t have yellow squash, zucchini makes an easy substitute. The flavor is slightly different but just as delicious. You can also use a mix of both for a pretty color contrast.

Looking for a little more protein? Add cooked bacon or crumbled sausage to the filling before baking. It adds a smoky richness that pairs beautifully with the creamy squash.

To make it gluten-free, swap the crackers for your favorite gluten-free breadcrumb or cracker alternative. Just make sure to still toss them with butter for that classic crunch.

Want to lighten things up a bit? Try using low-fat sour cream or plain Greek yogurt in place of the full-fat version. It’ll still be creamy and delicious, just a little lighter on the calories.

And for a more veggie-forward twist, throw in some chopped spinach or diced red bell pepper for extra color and nutrition. Just sauté them along with the squash so they’re tender before mixing into the casserole.

Don’t be afraid to get creative—once you have the base down, the possibilities are endless.

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