Easy Yellow Squash Casserole Recipe

There's something truly comforting about a warm, bubbly casserole coming out of the oven, especially when it's packed with the sunny flavor of yellow squash. This easy yellow squash casserole is creamy, cheesy, and topped with a perfectly golden crust that adds just the right crunch to every bite.

this Recipe

I discovered this recipe during a late-summer harvest, when my garden exploded with more yellow squash than I knew what to do with. Now, it's a staple at our dinner table and even makes regular appearances during the holidays. It’s simple, satisfying, and a guaranteed crowd-pleaser for picky eaters and veggie lovers alike.

Let’s dive into what makes this casserole so special.

Why You'll Love This Easy Yellow Squash Casserole

Get ready to meet your new favorite side dish. This easy yellow squash casserole has all the cozy vibes of a classic Southern recipe, but with minimal prep and maximum flavor.

First, it’s incredibly quick and simple to throw together. With just a handful of everyday ingredients and about 15 minutes of prep time, you can have it ready for the oven before your main dish is even finished cooking.

It’s also budget-friendly. Yellow squash is inexpensive, especially in season, and this recipe uses pantry staples like eggs, breadcrumbs, and cheese to keep things affordable without skimping on taste.

This casserole is family-friendly to the core. The creamy texture and cheesy topping make it appealing even to kids who usually avoid veggies. It’s the kind of dish that has everyone asking for seconds.

Finally, it’s versatile. Serve it alongside roasted chicken, grilled meats, or as part of a vegetarian spread. It’s equally at home at a weeknight dinner or a holiday feast.

Once you try it, don’t be surprised if it becomes a permanent part of your rotation.

Ingredients Notes

The charm of this yellow squash casserole lies in its simplicity. A short list of fresh ingredients comes together in a warm, cheesy bake that feels both comforting and fresh.

Yellow squash is, of course, the star here. Look for firm, medium-sized squash with smooth skin. Sliced thin, it cooks down beautifully into a tender base that soaks up all the creamy goodness around it.

Onion plays a supporting role, adding depth and a hint of sweetness. I like using a small yellow onion, diced finely so it melts into the background without overpowering the squash.

Cheddar cheese brings richness and sharp flavor. I recommend shredding your own rather than using pre-shredded bags – it melts more smoothly and gives the casserole that irresistible gooey texture.

Sour cream and eggs help create the luscious, custard-like filling. The sour cream adds tang and creaminess, while the eggs bind everything together so the casserole holds its shape when sliced.

To finish it off, breadcrumbs and butter make a golden, crispy topping. I often use crushed buttery crackers for extra flavor, but plain breadcrumbs or panko work just as well.

No fancy equipment needed – just a large skillet, a mixing bowl, and a baking dish. A mandoline slicer can be helpful if you want perfectly uniform squash slices, but a sharp knife will do the trick just fine.

How To Make This Easy Yellow Squash Casserole

This casserole comes together in a few simple steps, with most of the work happening on the stovetop before you slide it into the oven.

Start by preheating your oven to 350°F and greasing a medium baking dish. While that’s warming up, slice your yellow squash into thin rounds – aim for about ⅛ inch thick so they cook evenly and quickly.

In a large skillet over medium heat, melt a bit of butter and sauté the squash and onions together. Stir often to prevent sticking. Cook until the squash is tender and beginning to release its liquid – about 8 to 10 minutes. You don’t want it mushy, just soft enough to break down a little.

Once the vegetables are tender, remove the pan from heat. In a large mixing bowl, whisk together the eggs, sour cream, and shredded cheese. Season with salt and pepper, then fold in the warm squash and onions. The residual heat will help everything meld beautifully.

Transfer the mixture to your prepared baking dish, spreading it evenly. In a small bowl, mix your breadcrumbs or crushed crackers with melted butter, then sprinkle this over the top of the casserole. This is the secret to that golden, crunchy finish that makes this dish so satisfying.

Bake for 30 to 35 minutes, until the top is golden brown and the center is set. The edges will bubble and the aroma will tell you it’s ready. Let it sit for 5 to 10 minutes before serving – it firms up slightly as it cools, making it easier to scoop.

Storage Options

This casserole stores beautifully, which makes it ideal for meal prep or holiday planning.

If you have leftovers, allow the casserole to cool completely before transferring it to an airtight container. It will keep in the fridge for up to 4 days. Reheat individual portions in the microwave or the entire dish in the oven at 350°F until warmed through.

You can also freeze it. Wrap the entire baked casserole tightly in plastic wrap and foil, or use a freezer-safe container. It will stay good for up to 3 months. Thaw overnight in the fridge before reheating.

When reheating, you may want to add a sprinkle of fresh breadcrumbs or cheese to the top for a little crunch revival. Pop it under the broiler for a minute or two for an extra crispy finish.

Variations and Substitutions

One of the best things about this yellow squash casserole is how easy it is to tweak based on what you have or what you like.

If you don’t have yellow squash, zucchini works just as well. Or try a mix of the two for a colorful twist. Just make sure to cook it down well so your casserole doesn’t get watery.

You can play around with the cheese too. Swap cheddar for Monterey Jack, mozzarella, or even a little parmesan for a nuttier flavor. A combination of cheeses gives it extra depth and stretch.

For a lighter version, try replacing the sour cream with plain Greek yogurt. It keeps the creamy texture but cuts some of the fat. You can also use reduced-fat cheese if desired.

If you're going gluten-free, opt for gluten-free breadcrumbs or crushed rice crackers on top. The crispy topping is key to the texture, so don't skip it.

Want to make it heartier? Stir in some cooked, crumbled bacon or diced ham before baking. It turns this simple side into a main dish with just one added step.

However you make it, this casserole is a celebration of summer squash at its best – creamy, cheesy, and endlessly customizable. Give it a try and make it your own!

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