Old-School Squash Casserole

Squash casserole is a classic dish that can be found at almost any Southern dinner table or family gathering. While we love the squash itself, it is the creamy sauce (made from cheese, mayonnaise, and eggs) and crunchy, buttery cracker topping that keeps us coming back for seconds with this classic casserole.

Squash casserole is a staple dish found at meat-and-three diners and at church covered-dish suppers. It can stand on its own as a vegetarian main dish, but also pairs well with just about any protein (fried chicken is a traditional partner).

Learn how to make squash casserole. Plus, find out how to make it in advance and which ingredients are needed.

Our Tips for the Best Squash Casserole

Squash casserole is an easy dish to make, but these helpful tips make it even easier, especially if you're a first-timer.

• Drain the squash: To prevent your squash casserole from being too watery, it's important to get as much liquid out of the squash during the initial cooking process as possible. Straining the squash helps to remove excess water that leaches out of the cooked squash, and it cools the squash before it is added to the casserole. When sautéing, stir the squash often to release steam and prevent browning.
• Don't overcook: To keep the squash tender but not mushy, avoid overcooking the squash during the initial sauté. The squash still has one more cooking step to go (the bake in the oven) so it's better to slightly undercook it in the initial sauté so that it doesn't turn soupy during baking.
• Be gentle: Once cooked, gently fold the squash into the egg-cheese mixture to avoid mashing and breaking it into small pieces.

How To Make Squash Casserole

The full recipe for this squash casserole is below, but here's a brief recap:

• Step 1. Cook the squash until tender: Melt butter in a large skillet over medium-high heat. Now add squash, onion, and salt, stirring as you cook for about 10 minutes. (When ready, the squash will be just tender and the liquid will have evaporated.)
• Step 2. Drain squash: Transfer this mixture to a colander set over a bowl, and drain and discard any remaining liquid. Removing as much liquid as possible is important to avoid a soupy, soggy final casserole.
• Step 3. Make casserole mixture: Next, stir together eggs, sour cream, Swiss and Cheddar cheeses, mayonnaise, thyme, pepper, and salt in a large bowl.
• Step 4. Add squash: Fold in the squash mixture. Then spoon it into a lightly greased baking dish.
• Step 5. Make cracker crumb topping: Microwave the last portion of butter until fully melted. Toss the melted butter together with the crackers and Parmesan cheese until combined. Sprinkle this topping over the casserole.
• Step 6. Bake casserole: Bake it in the preheated oven until golden brown, about 20 minutes.

Squash Casserole Ingredients

This savory and satisfying recipe requires only affordable and readily available ingredients. You'll need:

• Unsalted butter: If you use salted butter, scale back on how much salt you use to keep the seasoning balanced.
• Yellow squash: You'll need about three pounds. You could also supplement the squash with zucchini if you want.
• Yellow onion: The slight sweetness of yellow onion pairs nicely with the squash.
• Eggs: Eggs are primarily used as a binding ingredient in casseroles. This recipe calls for two large eggs, lightly beaten. In addition to its binding properties, the eggs in this dish create a decadent, creamy sauce when combined with the cheeses and mayo.
• Sour cream: This provides the rich base for the creamy sauce. Greek yogurt would work, too.
• Parmesan, Cheddar, and Swiss cheeses: For an extra cheesy sauce. You can mix and match the cheeses you prefer, but this combination hits all the notes of tangy, salty, and nutty.
• Mayonnaise: Adds richness to the sauce without being too watery.
• Fresh thyme: This herb adds a bit of sweetness and herbal notes. You could also use oregano.
• Round buttery crackers (like Ritz): These make the perfect crisp topping to finish the casserole.

Making Squash Casserole Ahead of Time

Squash casserole is a great make-ahead option for dinners or holiday parties. Complete the recipe through Step 5, leaving the cracker crumbs off the top. Refrigerate up to 12 hours, or overnight, and then add the cracker crumbs before baking. You may need to add a few minutes to the total bake time to heat the casserole entirely since it will be cold when it starts baking.

You can also freeze squash casserole for a future bake. Again, leave the cracker crumb topping off the casserole until you're ready to bake. Thaw the frozen squash casserole overnight in the fridge, then add the crumbs and bake until heated through.

Southern Living Community Tips

The buttery topping is one of the standout features of this filling dish, but Southern Living community members note many ways to adapt it for equally scrumptious results.

"I used Italian-seasoned breadcrumbs instead of crackers and I still had a crunchy, crispy topping," Teresa Crawford says.

Another community member tried a different successful modification. "Instead of two sleeves of crackers, I used one and about half cup of Stove Top stuffing," the member writes. "That gave it some zing!"

Editorial contributions by Alesandra Dubin.