There is something deeply comforting about a bubbling dish of Southern Squash Casserole fresh out of the oven, isn’t there? It takes me right back to Sunday suppers where the sides were just as important as the main event. I distinctly remember being skeptical of squash as a kid, mostly because I’d only had the boiled, mushy kind until I tried this version. It was a total game-changer!
This recipe transforms humble yellow squash into something glossy, decadent, and totally crave-worthy. We aren’t just boiling veggies here; we are folding tender sautéed squash into a rich, creamy cheese sauce and crowning it with a buttery Ritz cracker topping that shatters perfectly with every forkful.
If you have ever worried about making a watery casserole, don’t stress. I’ve learned that the secret is to sauté the squash just until it’s barely tender, releasing the moisture before baking. Whether you are looking for the perfect holiday side dish or want to use up a bounty of summer produce, this recipe delivers pure comfort without the fuss.
Table of Contents
Old-Fashioned Southern Squash Casserole
Ingredients
The Squash Base
- 3 lbs yellow squash sliced ¼-inch thick (about 5 medium squash)
- 1 medium yellow onion chopped
- 3 tbsp unsalted butter
- 1 tsp salt plus more to taste
- ½ tsp black pepper
The Creamy Filling
- 2 large eggs lightly beaten
- 8 oz sour cream
- 1 cup sharp Cheddar cheese freshly shredded
- ½ cup Swiss cheese freshly shredded
- ½ cup mayonnaise
- 2 tsp fresh thyme chopped (or ½ tsp dried)
The Cracker Topping
- 2 sleeves Ritz crackers crushed (about 1½ cups crumbs)
- 3 tbsp unsalted butter melted
- ¼ cup Parmesan cheese shredded
Instructions
- Preheat and Prep: Preheat your oven to 350°F (175°C). Lightly grease a 9×13 or 8×8 baking dish with non-stick spray.
- Sauté the Veggies: In a large skillet over medium-high heat, melt the 3 tablespoons of butter. Add the sliced squash and chopped onion. Season generously with salt and pepper. Cook for 8–10 minutes, stirring occasionally, until the squash is just tender and most of the liquid has evaporated.
- Drain Thoroughly: Transfer the cooked squash mixture to a colander set over the sink. Let it drain well to remove excess moisture—this is the secret to a non-watery casserole!
- Make the Sauce: In a large bowl, whisk together the eggs, sour cream, mayonnaise, Cheddar cheese, Swiss cheese, and thyme until creamy and combined.
- Combine: Gently fold the drained squash and onions into the cheese mixture until everything is evenly coated. Pour the mixture into your prepared baking dish.
- Add the Crunch: Crush the Ritz crackers (keep them a bit coarse for texture!). In a small bowl, toss the cracker crumbs and Parmesan cheese with the melted butter until coated. Sprinkle evenly over the casserole.
- Bake: Bake for 20–30 minutes, or until the top is golden brown and the filling is bubbling around the edges.
- Serve: Let the casserole rest for 5 minutes before serving to help the filling set. Enjoy!
Notes
- Avoid Pre-Shredded Cheese: For the glossiest, smoothest sauce, grate your own cheese. Pre-bagged cheese has anti-caking agents that can make the sauce grainy.
- Make Ahead: You can assemble the casserole (without the topping) up to 24 hours in advance. Store covered in the fridge. Add the topping just before baking and add 5-10 minutes to the cook time.
- Storage: Leftovers can be stored in an airtight container in the refrigerator for up to 3 days.
Nutrition
Ingredients You’ll Need
Here is everything you need to whip up this cheesy delight. I love that these are simple pantry staples you likely already have on hand!
For the Squash Base:
- 3 pounds yellow squash, sliced ¼-inch thick and cut into half-moons (about five medium squash)
- 1 yellow onion, roughly chopped for savory depth
- 3 tablespoons unsalted butter
- Salt and black pepper, to taste
For the Creamy Filling:
- 2 large eggs, lightly beaten
- 8 ounces of sour cream (full-fat works best for texture!)
- 1 cup sharp Cheddar cheese, freshly shredded
- ½ cup Swiss cheese, freshly shredded (adds a lovely nutty flavor)
- ½ cup mayonnaise
- 2 teaspoons fresh thyme, chopped
- Salt and black pepper, to taste
For the Buttery Cracker Topping:
- 2 sleeves Ritz crackers, coarsely crushed
- 3 tablespoons unsalted butter, melted
- ¼ cup Parmesan cheese, freshly shredded
How to Make Southern Squash Casserole
Get ready to make your new favorite side dish! These steps are straightforward, but I’ve included a few specific tips to ensure you achieve the perfect creamy texture without the dreaded “soggy bottom.”
1. Prep and Sauté the Vegetables
Preheat your oven to 350°F and lightly grease an 8×8-inch baking dish with cooking spray. Slice your yellow squash into ¼-inch-thick half-moons and give the onion a rough chop.
In a large skillet over medium-high heat, melt three tablespoons of butter. Throw in the squash and onion, seasoning generously with salt and pepper. Cook this for about 10 minutes, stirring often. You want the squash to be just tender in the center and, most importantly, for the liquid to evaporate. This sautéing step packs a punch of flavor that boiling just can’t match!
2. The Crucial Step: Drain Thoroughly
This is the moment that separates a good squash casserole recipe from a great one. Transfer your cooked squash mixture to a colander set over the sink. Let it drain completely, discarding any accumulated liquid.
I recommend gently pressing it with the back of a spoon to remove excess moisture. This critical step prevents moisture drainage issues later and ensures your casserole stays rich and creamy, not watery.
3. Mix the Creamy Cheese Binder
While the squash is draining, grab a large mixing bowl. Whip up the binder by stirring together the lightly beaten eggs, sour cream, shredded Cheddar, Swiss cheese, mayonnaise, and fresh thyme. Add a pinch of salt and pepper.
Whisk until the ingredients are smoothly combined. The mixture should look thick and creamy. The combination of mayonnaise and sour cream creates a glossy, vibrant sauce that binds everything together perfectly.
4. Combine and Transfer
Gently fold the drained squash and onion mixture into your cheese mixture. Stir carefully so that you coat every piece without breaking the squash down into a mushy mess. Spoon this entire mixture into your prepared baking dish, spreading it out evenly to the edges.
5. Add the Crunchy Topping
Place your Ritz crackers in a zip-top bag and crush them with your hands. I prefer leaving them a bit coarse rather than turning them into dust; that texture provides a great contrast to the soft filling!
In a medium bowl, melt the remaining three tablespoons of butter (about 25 seconds in the microwave usually does it). Toss the crushed crackers and Parmesan cheese with the melted butter until every crumb is glistening. Sprinkle this golden goodness evenly over the top of the casserole.
6. Bake to Golden Perfection
Pop the uncovered dish into your oven and bake for 20-30 minutes. You are looking for a golden brown top with bubbling edges. The cracker topping should be beautifully crisp. Let it rest for about 5 minutes before serving, allowing the filling to set slightly. It makes serving much easier!
Tips for the Best Results & Variations
I have made this Southern Squash Casserole more times than I can count, and I’ve picked up a few tricks along the way. Here is how to ensure success and how to switch things up if you’re feeling adventurous.
- Avoid Pre-Shredded Cheese: I know it’s convenient, but pre-shredded cheese is coated in anti-caking agents that prevent it from melting smoothly. Opt for blocks of Cheddar and Swiss and shred them yourself for the silkiest sauce.
- The “Soggy” Fix: If you find your squash releases a lot of water even after sautéing, you can lay the cooked slices on paper towels for a minute before mixing them with the cheese. It’s an extra step, but totally worth it if your squash is extra fresh and juicy.
- Make It a Meal: Want to turn this easy squash casserole into a main dish? You can stir in 2 cups of cooked, shredded chicken or turkey before baking. It’s a fantastic way to use up holiday leftovers!
- Spice It Up: If you like things with a bit of a kick, add a pinch of cayenne pepper or a dash of hot sauce to the cheese mixture. It adds a subtle heat that cuts through the richness beautifully.
- Cracker Swap: While I am a die-hard Ritz fan for this recipe, you can also use crushed Cheez-Its for extra cheddar flavor or panko breadcrumbs for a lighter, crispier crunch.
Storage & Make-Ahead Tips
This is a fantastic make-ahead squash casserole. You can assemble the entire dish (minus the cracker topping) up to 24 hours in advance. Cover it tightly and store it in the fridge. When you’re ready to eat, add the topping and bake, adding about 5-10 extra minutes to the cooking time since it’s starting cold.
What to Serve With Southern Squash Casserole
Because this dish is rich and cheesy, I like to pair it with proteins that can stand up to those bold flavors. Here are a few of my favorites:
- Fried Chicken: It is a cliché for a reason! The crispy skin of the chicken pairs perfectly with the creamy, soft texture of the casserole. It creates the ultimate Southern comfort food plate.
- Holiday Ham: The saltiness of a glazed ham is an excellent counterpoint to the slightly sweet, creamy squash. This is a staple on our holiday table.
- Grilled Pork Chops: For a standard weeknight dinner, simple grilled pork chops are a great option. The smokiness from the grill complements the nutty Swiss cheese in the casserole.
- Fresh Greens: Balance the richness with a side of collard greens or a crisp, acidic salad dressed with a vinaigrette.
Frequently Asked Questions
How do you prevent squash casserole from being watery?
This is the most common issue! The key is twofold: sauté the squash first instead of boiling it, and then drain it thoroughly in a colander. Pressing out the excess liquid ensures your sauce remains thick and creamy rather than soupy.
Can you freeze squash casserole?
Technically, yes, but I do not recommend it. Squash has a high water content, and freezing it can change the texture, making it mushy when reheated. However, if you must, freeze it unbaked and without the cracker topping. Thaw it in the fridge overnight before baking.
What kind of squash is best for casserole?
Yellow summer squash (crookneck or straightneck) is the traditional choice for this Southern side dish. However, you can absolutely substitute zucchini or use a 50/50 mix of yellow squash and zucchini for a pop of color!
Final Thoughts
I hope you love this Old-Fashioned Southern Squash Casserole as much as my family does. It is one of those dinners that feels special enough for a holiday but is easy enough for a Tuesday night.
The combination of tender squash, melting cheese, and that buttery, crunchy topping is just absolutely delicious. Give it a try, and let me know in the comments if you stuck to the classic Ritz topping or tried a variation of your own. You’ve got this!
