The Easy Southern Casserole I've Been Making on Repeat

Rich and comforting, Southern squash casserole is one of those vegetable side dishes that’s not really about the vegetables. Yes, it’s packed with yellow squash cooked until tender. But its appeal lies squarely in its buttery cracker topping. That distinctive yellow squash flavor comes through, but everyone knows all that squash is a supporting player to the golden brown crushed crackers doused in melted butter.   

This easy casserole is a side dish welcome at any potluck, Sunday dinner, or gathering. It’s commonly found as an option at Southern meat-and-three restaurants, but it’s so simple to make at home.

The Ever Adaptable Squash Casserole

Open up any community cookbook published in the 1970s or 1980s and you will likely see multiple versions of squash casserole recipes. Often the cookbooks’ only squash recipes, in fact. This goes for many American community cookbooks, not just Southern ones, but as far as I know, this casserole originated in the South. 

I perused my own treasured cookbook collection and easily found many versions; one cookbook even had three different recipes on the same page! Though so many iterations exist, they’re all essentially cooked summer squash and onions bound with something rich and creamy: any combination of eggs, cheese, mayo, sour cream, canned condensed soup, or all of the above. Plus, the aforementioned crumb topping, which can be breadcrumbs but really should be crackers because, in this instance, they’re just better.

I wanted to keep it simple and streamlined, and in my experiments, mayonnaise plus an egg and some grated cheese delivered the right balance of substance without overwhelming the squash. Plus, most everyone has eggs, mayo, and cheese in the fridge, which allows you to make this casserole on a whim if you have abundant yellow squash.

Switch It Up

• Yellow squash in this casserole is iconic, but you can use zucchini or other tender summer squash.
• Cheddar cheese delivers a deep color and good character to the casserole, but any cheese you like works. I actually love it with Velveeta! Mixing Swiss or Parmesan with the cheddar adds even more flavor.
• I prefer Club or Ritz crackers in this recipe, while my mom says Cheez-It or Goldfish are superior. Even plain old saltines work, though.
• Yes, you are tossing the cracker crumbs in extra butter, but starting with good buttery crackers in the first place makes a lot of difference. I used Club crackers and off-brand ones in my testing, and the version with the Club crackers easily beat out the one with knockoffs.  
• If mayo makes you shudder, you can replace the mayonnaise with sour cream, adding a little extra salt.
• A little fresh or dried thyme adds a nice dimension.

More Casserole Sides

• Copycat Cracker Barrel Hashbrown Casserole
• Cheesy Spaghetti Squash Casserole
• Green Bean Casserole from Scratch
• Onion Potato Gratin

Preheat the oven to 350°F. 

Put the butter in an 8x8-inch or 2-quart casserole dish and pop it in the oven to melt as it preheats.

Toss the crumbs with the butter:

Once the butter has melted (it usually takes 5 to 8 minutes), add the cracker crumbs to the dish and toss to coat. Remove the buttered crumbs to a bowl and set the bowl and the now-greased dish aside.

Steam the squash and onion, then drain:

Put the squash and onion pieces in a large skillet with 1 cup water. Bring to a boil over high heat and cook, stirring occasionally, until the squash is tender, about 10 min.

Strain the squash and onion into a sturdy colander in the sink. With the vegetables still in the colander, mash them with a potato masher just until they’re chunky. This allows even more moisture to drain out, which will keep your casserole from getting too watery.

 Finish the assembling the casserole:

Beat the egg in a large bowl. Add the mayonnaise and beat until combined. Fold in the cheese, salt, and pepper. Add the mashed squash (it’s okay if it’s still hot) and mix until combined.

Bake and serve: 

Scrape into the greased dish or pan. Top evenly with the buttered cracker crumbs.

Bake until the center is set and the crackers are lightly browned, about 30 minutes. Cool for at least 5 minutes before serving. Refrigerate leftovers for about 5 days. 

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