Cheesy Yellow Squash Casserole

I am always on a year-round hunt for new and delicious seasonal side dishes. At any given BBQ or potluck, I will regularly pass up mains to eat a whole plate of sides. My plate will consist of potato salad, Southern pecan bread, Southwest quinoa salad, and lately, a generous serving of this squash casserole.

Cheesy Yellow Squash CasseroleWhy You’ll Love This Squash Casserole RecipeWhat You’ll NeedHow to Make Squash CasseroleCan I Make Squash Casserole Ahead of Time?Tips for SuccessServing SuggestionsHow to Store & Reheat ExtrasCan I Freeze This Squash Casserole?More Southern Side DishesGet the Recipe

A good casserole recipe is just the best. Is it a meal? Is it a side dish? In my house, it’s both! This squash casserole recipe is a perfect example of a versatile dish that doubles as a side and a main. In my books, that’s the definition of the best of both worlds.  This cheesy summer squash casserole is a staple of Southern cuisine. It packs all the classic ingredients into one dish: tender summer squash, sour cream, melty cheese, and Ritz crackers (of course). It’s a real time saver on busy weeknights, easy to customize, and just all around comfort food.  If you’re on the lookout for more easy casserole recipes, be sure to check out this cheesy potato casserole, this broccoli cheese casserole, and this cheesy cauliflower casserole as well!

Why You’ll Love This Squash Casserole Recipe

Squash casserole is constantly on the menu at my house! Here’s why we’re such big fans:

Creamy and cheesy. This tender yellow squash is smothered in a mixture of sharp cheddar, parmesan cheese, and sour cream. You’ll fall head over heels in love from the first cheesy bite! Perfect texture. The squash itself is soft and tender but the Ritz cracker topping is so buttery and adds the perfect amount of crunch! Quick and simple. This casserole can be assembled in 20 minutes, and only takes 45 minutes from start to finish!

What You’ll Need

Here’s an overview of everything you’ll need to make this Southern favorite. Please refer to the recipe card for full amounts and instructions!

Butter: Salted or unsalted, you’ll need butter for sautéing the veggies for the casserole, as well as for mixing into the buttery cracker topping. Yellow Squash: This recipe calls for about 5 medium squash, sliced into rounds. You can use any combination of yellow or green summer squash, see below. Onion: Yellow onion bulks up the dish and adds bucket loads of flavor! Herbs and Spices: I season my casserole with a combo of minced garlic, salt and pepper, cayenne pepper and dried thyme. Eggs: A pair of eggs bring some welcome structure to the casserole so that it sets up nicely when baking. Sour Cream: For that delicious creaminess and tang. Is it even a Southern casserole without it? Cheese: I stick with classic, freshly grated cheddar and parmesan cheese. Other types of cheeses will also melt nicely in this recipe. Good options are Colby or Monterey Jack, shredded mozzarella, or Gruyere cheese. Ritz Crackers: You’ll need about two sleeves of these buttery beauties for the squash casserole filling, and for the crunchy topping. Definitely try to get your hands on the real deal, or a generic version if you can. However, another salty cracker will also work, if need be.

Can I Use Another Kind of Squash?

Definitely. This casserole is especially great in the summer months when squash is in season, and you can use yellow squash, zucchini, or any combination of the two. Zucchini will not be as sweet as yellow squash in this recipe, but it will still be delicious! I also love to adapt this recipe into a butternut squash casserole in the fall.

How to Make Squash Casserole

While your oven is preheating to 350°F, you can pull together this summer squash casserole in just a few easy steps:

Sauté the veggies. In a large skillet, sauté the onions with butter until softened, then add in the squash rounds. Once the squash is cooked tender, in go the garlic and seasonings. After another minute or two, take the pan off the heat and drain the liquid (if any). Prepare the filling. Whisk the eggs, sour cream, and both cheeses together in a bowl. Next, stir in the squash and onions, followed by about a cup of the crushed Ritz crackers. Pour the filling into a baking dish coated with cooking spray. Make the topping. In a new bowl, combine the rest of your crushed crackers with melted butter. Mix in some parmesan cheese, and then spread the cracker topping over the squash mixture in the pan. Bake the casserole. Bake the casserole until the top is gloriously golden and the filling is bubbly, then serve while it’s still warm and melty!

Can I Make Squash Casserole Ahead of Time?

Absolutely! I am all about a recipe you can make ahead for BBQs, entertaining, or potluck dinners. It just so happens that this squash casserole is perfect to prep up to a day in advance, and then pop into the oven when you’re ready to serve it. Making this casserole ahead is super easy. Simply prep the ingredients and assemble the casserole per the recipe, cover, and refrigerate until it’s time to bake. I recommend taking your squash casserole out of the fridge 20 minutes before it goes into the oven, to take the chill off. Then just add a few extra minutes to the baking time, making sure the casserole is warmed throughout.

Tips for Success

This squash casserole is an incredibly forgiving recipe, but here are a few pointers so you can really nail it:

Use freshly grated cheese. I’m all for a shortcut in most cases, but I highly recommend grating your cheeses fresh for this casserole! The pre-shredded and pre-grated cheese that comes in bags from the store tends to have a waxy texture (to keep it from clumping) that just won’t melt as nicely. Weigh the squash. This recipe calls for 3 pounds of yellow squash (roughly 5 medium sized specimens). If you can, it’s easiest to weigh your squash with a kitchen scale to be sure you end up with the correct amount. Since squash sizes vary a lot, it’s sometimes tricky to go by the number of squash alone. Bulk it up as a main. Turn a vegetable side into a main by bulking up this casserole with your choice of protein. Add shredded rotisserie chicken into the squash filling for an easy all-in-one meal. See the next section for more serving ideas!

Serving Suggestions

I’ll say it once more: this easy casserole is a great summer recipe when yellow squash is in season. I love to make and serve this with summer salads, BBQ, burgers, and just about anything I can put on the grill.  Here are some of my favorite summertime dishes to serve it with:

Honey Citrus Grilled Chicken Crispy Crab Balls Air Fryer Chicken Tenders Cheeseburger Sliders

Honestly, squash casserole is pure comfort food that can absolutely be enjoyed anytime of year. It works perfectly as a hearty vegetarian main dish on meatless Monday. Or, enjoy it as a classic holiday side dish at Thanksgiving or Christmas, alongside green beans, mashed potatoes, and rolls.

How to Store & Reheat Extras

Yellow squash casserole stores really well. This is the best way to preserve it for later:

To store. Store your casserole leftovers airtight in the fridge for up to 3 days. You can wrap the whole dish or transfer it to a lidded container. To reheat. Reheat servings in the oven, in an oven-safe dish at 350ºF until warmed through. The microwave can also speed things up a bit, just heat the casserole in increments until it’s warm again.

Can I Freeze This Squash Casserole?

Due to zucchini being a watery vegetable, and this being a dairy-heavy casserole, I wouldn’t recommend it for freezing. Squash casserole leftovers will freeze for up to 3 months as a last resort, but the texture simply won’t be the same. If you are dying to freeze it, wrap the casserole airtight in plastic wrap and foil. Thaw it in the fridge and sprinkle on more Ritz cracker topping when you’re ready to reheat it.

More Southern Side Dishes

These Southern side dish recipes are perfect for barbecues, potlucks, picnics, and more!

Southern Pecan Bread Creamy Cheesy Cornbread Southern Style Cornbread Dressing The BEST Skillet Biscuits

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