This tasty southern squash casserole combines yellow squash, zucchini, onions, and garlic into a creamy cheddar cheese base, topped with buttery crackers. It is a quick and easy side dish that everyone loves.
This is a great summer recipe for using up all those bushels of garden squash. Serve it with country-style ribs or marinated grilled chicken. In the fall and winter months, serve it with crockpot pork chops or crockpot beef tips and homemade mashed potatoes.
Ingredient Notes and Substitutions
See the complete list of ingredients below on the recipe card.
- Squash: You can use yellow squash or zucchini. I like a combination of the two.
- Cheese: Any shredded cheddar cheese, including regular, mild, sharp, smoked, or white cheddar.
- Mayonnaise: I love Duke’s mayo, but you can use your favorite brand.
- Sour cream: Use full-fat for the best baking consistency and flavor.
- Fresh herbs: Such as chopped fresh parsley, thyme, rosemary, or dill.
- Topping: I like a buttery cracker topping. A cornflake topping or a panko bread crumb topping, like in these cheesy potatoes, is also delicious.
How to Make Squash Casserole
This is a summary version; for the complete list of ingredients and instructions, please refer to the recipe card below.
- Sauté the squash just until tender. Put it in a colander in the sink to drain any excess moisture.
- Cook the onion over medium heat until tender. Reduce the heat to low and add the garlic, cooking for a minute.
- In a large bowl, mix the eggs, cheddar cheese, mayonnaise, sour cream, salt, black pepper, and a teaspoon of fresh herbs.
- Gently toss the veggies in the egg mixture and spoon into a greased 2-2 1/2 quart casserole dish.
- Mix the coarsely crushed crackers with melted butter and sprinkle over the top of the squash mixture.
- Bake at 350 degrees until lightly browned or for 25-30 minutes.
Preparation Tips
- Don’t cut the zucchini too thin. 1/4-1/3 inch is best.
- Sautéing the squash helps cook off excess moisture, but don’t cook it too long. You want it ever so slightly fork-tender with a fair amount of structure to it. Never soggy or mushy
- Drain the zucchini in a colander in the sink while you work the rest of the recipe. Carefully remove any moisture in the skillet before adding more butter and cooking the onion and garlic.
How To Make This Casserole Ahead of Time
You can make this casserole up to 24 hours ahead of time. Prepare the casserole, but do not prepare or add the topping. Cover it with plastic wrap and store it in the refrigerator.
When ready to bake, remove the casserole 30-40 minutes before baking to bring it to room temperature. Mix the cracker crumbs and butter. Sprinkle over the casserole and bake.
How To Freeze Squash Casserole
For the best results, freeze before baking. Prepare the casserole in a freezer-safe dish, but do not prepare or add the topping. Cover it with 2 layers of plastic wrap and freeze for up to 2 months. Thaw in the refrigerator overnight. When ready to bake, remove the casserole 30-40 minutes before baking to bring it to room temperature. Mix the cracker crumbs and butter. Sprinkle over the casserole and bake as instructed.
Squash Casserole
Ingredients
- 4 tablespoons butter
- 4 medium yellow squash or zucchini cut into 1/4 inch rounds
- 1 medium yellow onion, finely chopped
- 2 cloves garlic, minced
- 2 large eggs
- 1½ cups shredded sharp cheddar cheese
- ¼ cup mayonnaise
- ¼ cup sour cream
- ½ teaspoon sea salt
- ¼ teaspoon freshly ground black pepper
- 2 teaspoons chopped fresh thyme, divided
- 1 sleeve buttery crackers (like Ritz), coarsely chopped
Instructions
- Preheat oven to 350 degrees. Grease a 9×13-inch casserole dish or a dish close to equivalent in size.
- Melt 1½ tablespoons butter in a large skillet over medium heat. Sauté the squash just until tender. Place it in a colander in the sink to drain any excess moisture. Carefully drain or wipe the skillet of any added moisture.
- Melt 1 tablespoon butter over medium heat. Add the onion and cook until tender. Reduce the heat to low and add the garlic, cooking for a minute.
- In a large bowl, mix the eggs, cheddar cheese, mayonnaise, sour cream, salt, black pepper, and thyme. Gently toss the veggies in the egg mixture and spoon them into the prepared casserole.
- Melt 1½ tablespoons butter. Mix the crushed crackers with the melted butter and sprinkle them over the top of the squash mixture. Bake for 25-30 minutes or until lightly browned. Let the casserole rest for 5 minutes before serving.
Hadley
I have had tons of squash and never knew how to cook it! Thank you for sharing this easy to follow recipe – I really appreciate it. It was delicious and even my picky kids loved it.
Sammy
It definitely is the weather to start eating more comfort food, although I do cook with squash I do not cook it enough or try other things. This sounds like the perfect home comfort meal
Mary
I love squash, but I can’t seem to find creative recipes. But this is a great one! I will have to try your casserole soon.
Beth Pierce
Thanks, Mary! Enjoy!