This Easy Squash Casserole recipe is an old fashioned Southern classic casserole made with yellow squash, cheese, mayonnaise, and sour cream. Topped with crushed butter crackers, it's a 10-ingredient recipe that's guaranteed to be delicious.
This Southern staple is made with layers of fresh squash, a creamy cheese sauce and a rich, crunchy, butter cracker topping, making this Easy Squash Casserole comforting and satisfying all in one bite. It's simple to prepare and always a crowdpleaser!
Whether it's an indulgent side as part of a spread, or a meal unto itself, this Southern Squash Casserole is a great way to use up any leftover squash, and the perfect way to serve up Southern comfort at your own dinner table.
If you like this casserole, be sure to check out these other easy side dishes. Some of our favorites are this Healthy Pasta Salad, these delicious Green Beans with Bacon and Onion, and our refreshing Tomato and Cucumber Salad.
Table of Contents
Why This Recipe Is the Best
- Simple to Prepare: With ingredients that are easy to shop for and prep, plus a simple method, this nostalgic dish is so easy to make, anyone can do it.
- Classic and Comforting Casserole: This squash casserole is an oldie and a goodie! Especially with its' southern roots, this recipe is heartwarming, comforting and delicious all loaded into one casserole dish
- Great Way to Use Squash: In the summer months, you might find yourself with some extra squash laying around. So use it up in an exciting, satisfying way - in this casserole!
- Southern Side or Main for Any Occasion: This casserole isn't just a regular casserole, it's rich and creamy and full of flavor and southern tradition. Serve it as a side or special main dish at any of your next gatherings - it's sure to be a crowd-pleaser.
What Is Old Fashioned Squash Casserole?
Old Fashioned Squash Casserole is a classic, comfort food that can be found at almost any southern dinner table or spread. This dish is commonly served at family gatherings, parties and potlucks, and it's truly a staple in the South.
As it goes, southerners aren't afraid to smother their veggies in cream and butter, and that certainly rings true with this recipe - no complaints here! It's traditionally made with fresh squash, a rich and creamy sauce, topped with buttery crackers, then baked until golden and every family has their own version. This is a signature dish we are all about!
Ingredients
Scroll Down for Ingredient Amounts Listed in the Recipe Card Below
- Salted Butter: The main fat the star ingredient, squash, and onions are sauteed in. It adds a rich, smooth flavor, and I like salted here to give the squash some extra seasoning.
- Yellow Squash: Yellow squash is sweet, mild, and tender, which makes it the perfect base for this casserole. It has the perfect texture and flavor, but if you need a substitute, we recommend zucchini.
- Onion: An aromatic to help flavor the casserole - we like sweet onions here. The subtle sweetness pairs well with the squash and balances the rich cream sauce.
- Salt and Pepper: Always be sure to season as you go to bring out all of the flavors of each ingredient.
- Sour Cream: Rich, tangy, and delicious, this helps to make the base of the creamy, velvety sauce.
- Mayonnaise: Provides a richness to the sauce.
- Cheddar, Swiss, and Parmesan Cheeses: The key ingredients for the decadent cheese sauce! Cheddar and Swiss are sharp and melty, while parmesan adds a nice nutty note.
- Eggs: Works as a binder for all of the casserole ingredients. Also brings a richness to the dish as it's combined with sour cream and mayonnaise.
- Butter Crackers: Rich, crunchy and crispy, these are the perfect topping to finish off the casserole.
TOOLS YOU’LL NEED
- 2 Quart Baking Dish
- Measuring Cups and Spoons
- Silicone Spatula
- Mixing Bowls
- Cheese Grater
- Cutting Board
- Chef's Knife
How To Make Easy Squash Casserole
- Preheat oven to 350°F and meanwhile, grease a 9"x9" pan or 2 quart baking dish with butter or cooking spray.
- Melt 2 tablespoons of butter in a large skillet over medium-high heat. Add the sliced squash and chopped onion to the skillet. Season with 1 teaspoon of salt and cook until the squash is tender, about 10 minutes.
- Gently stir the squash and onions occasionally, then pour into a colander to drain any excess moisture.
- In a large bowl, combine sour cream, mayonnaise, ½ cup of the sharp cheddar cheese, half of the Swiss cheese, half of the Parmesan cheese, remaining salt, and black pepper.
- Fold the cooked squash and onions into the creamy mixture. Once combined, fold the whisked egg into the mixture. Pour into the prepared baking dish.
- Melt the remaining butter in a medium mixing bowl. Combine with crushed crackers and remaining cheeses. Evenly distribute on top of the squash base.
- Bake in the preheated oven 20-25 minutes, or until bubbly and golden brown.
Expert Tips
- Use a Mandoline: Carefully use a mandoline to slice your squash into uniform discs, quickly.
- Remove Excess Water. To avoid a watery casserole, be sure to remove as much water from the squash after cooking it. Be sure to strain it well afterwards, and you should be good to go.
- Avoid Overcooking The Squash: No one likes mushy squash, so to avoid this, ere on the side of undercooking the squash during the initial saute. Remember, it'll get cooked again in the casserole, so you don't need to cook it until it's overly soft in the skillet.
- Shred Your Own Cheese: It can be tempting to use the pre-shredded stuff, but take the time to shred and grate your own cheeses, it's worth it. The pre-shredded cheese in the bag is often coated and doesn't have the same flavor or consistency as shredding your own.
- Let Casserole Rest Before Serving: Once your casserole is bubbly and hot, remove it from the oven and let it rest for 10 minutes. Resist the urge to dig in right away, it's so worth it once it's set.
Variations and Substitutions
- Switch Up The Topping: Butter crackers are a decadent topping, but try some other crispy, crunchy toppers. Seasoned Italian breadcrumbs would be nice, mixing in additional parmesan to panko breadcrumbs would be delicious, or you could even use a boxed stuffing mix or canned fried onions for extra flavor and texture.
- Use Zucchini: If you've got green zucchini on hand too, or if you can't find yellow squash, zucchini works in this recipe too.
- Lighten it Up: If you want to make a lighter version, use Greek yogurt instead of sour cream.
Storing and Freezing Leftovers
- Fridge: Store any cooled leftovers in an airtight container for up to 3-5 days. Simply reheat when you're ready to eat.
- Freezer: You can also freeze any leftover in the freezer in an airtight container for up to 3 months. Defrost in the fridge, then reheat in the oven or microwave.
- Make Ahead: This is a great make-ahead recipe, too. Prepare it according to the recipe, just leave the butter crackers off the top. You can either refrigerate it or freeze it then thaw, and when you're ready to serve, add the cracker crumbs to the top. Bake as usual, and enjoy!
Frequently Asked Questions
Removing any excess water from the squash is key to avoiding a watery, thin casserole. Be sure to fully drain the squash after you saute it and you'll be set.
This is such a tried and true, old-school recipe so we love to stick to the traditional ingredients, but if you've got zucchini, bell peppers or broccoli florets, you could always add these in for some extra veggies and color.
Absolutely! Freeze it in an airtight container for up to 3 months. You can also freeze in smaller portions for convenience. Just thaw in the fridge and reheat in the oven when you're ready to serve. You can also make this ahead of time and freeze it before baking - just wait to add the cracker topping until it's thawed and you're ready to put it into the oven.
The best substitute for yellow squash would be zucchini here. They're similar in texture and flavor.
More Delicious Casserole Recipes
Old Fashioned Easy Squash Casserole
Ingredients
- 6 tablespoons salted butter divided
- 1 ½ pounds yellow squash cut into ¼-inch discs
- 1 cup diced sweet onion
- 1 ½ teaspoons salt divided
- ½ cup sour cream
- ¼ cup mayonnaise
- ¾ cup shredded sharp cheddar cheese divided
- ½ cup shredded Swiss cheese divided
- ½ cup shredded parmesan cheese divided
- 1 large egg lightly beaten
- ½ teaspoon black pepper
- 32 buttery round crackers crushed
Instructions
- Preheat oven to 350°F. Grease an 9"x9" pan or 2 quart baking dish with butter or cooking spray.
- Melt 2 tablespoons of the butter in a large skillet over medium-high heat. Add the sliced squash and chopped onion to the skillet. Season with 1 teaspoon of the salt. Cook until the squash is tender, about 10 minutes. Gently stir occasionally. Pour in a colander to drain any excess moisture.
- In a large bowl, combine sour cream, mayonnaise, ½ cup of the sharp cheddar cheese, half of the Swiss cheese, half of the Parmesan cheese, remaining salt, and black pepper.
- Fold the cooked squash and onions into the creamy mixture. Once combined, fold the whisked egg into the mixture. Pour into the prepared baking dish.
- Melt the remaining butter in a medium mixing bowl. Combine with crushed crackers and remaining cheeses. Evenly distribute on top of the squash base.
- Bake in the preheated oven 20-25 minutes, or until bubbly and golden brown.
Grace
thank you so so much for this recipe I happen to grow yellow squash and wS wondering how and what to do with it. and what do you know you popped in and bingo you made my day. you are awesome. thanks again can't wait for your next recipe.
Laura Ashley
Thank you so much!! I'm so happy you saw it and liked it so much too! It'll be perfect for that abundant squash this summer 🙂
Debi Driscoll Powell
This was an absolute home run with my family!! Super flavorful, almost comfort food where you could just dish out a bowl and sit on the couch and feel better instantly! I’m so glad I almost doubled it and used a 9 x 13 so I could have leftovers for the weekend because it is delicious leftover!
I made fresh green beans and blackened tilapia with it tonight, but it would be good. Good with any protein. Thanks for yet another fabulous recipe Laura!
Laura Ashley
This flat out makes my heart SO happy to hear! THANK YOU So much! I'm so happy you liked it so much!! 🙂
Nikki
My favorite summer casserole! So tasty!
Laura Ashley
That's awesome! Thank you SO MUCH!!!
Jules
We love squash and I'm always looking for new ways to use it. This casserole was so easy to make and delicious.
Laura Ashley
AWESOME! I'm so happy you liked it!
Mandy
We love this squash casserole recipe! Tasty and so easy to make.
Laura Ashley
AWESOME! So happy you liked it so much!! 🙂
Betty
I made this and it is delicious! Thank you so much for the recipe.
Laura Ashley
Thank you so much!! I'm so happy you liked it!
Lara
This recipe was absolutely amazing. We served it alongside steaks, shrimp and grilled asparagus for a fantastic Father’s Day meal! Will definitely be making it again. Thank you for a wonderful recipe.
Laura Ashley
Thank you so much!! I'm so happy you liked it so much! It means a lot to me!
Jules
I love summer squash and am always looking for new recipes that use it. We absolutely loved this recipe. It made a delicious side dish and next time I'm going to cut up some kielbasa and serve it as our main meal.
Laura Ashley
YUM!! With kielbasa sounds amazing!! I'm so happy you made it and liked it so much!!
Kathleen
I have been searching for a squash casserole recipe that my SIL made years ago—this is it! It's so creamy and so good that even non-squash lovers eat it up! Thank you!
Laura Ashley
Oh that is wonderful to hear! THANK YOU so much!