Southern Squash Casserole (Just Like Grandma Made)

Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Ingredients: 2 pounds yellow squash ((sliced ¼-inch thick)); 1 large sweet onion ((chopped)); 2 tablespoons salted butter; 1 teaspoon kosher salt; ½ teaspoon black pepper; ½ teaspoon garlic powder; ¼ teaspoon paprika; 2 large eggs ((lightly beaten)); ½ cup sour cream; ½ cup mayonnaise; 1 ½ cups shredded sharp cheddar cheese; 1 sleeve Ritz crackers ((about 35 crackers, crushed)); 4 tablespoons salted butter ((melted)); Dried parsley (for garnish (optional))

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Some dishes just taste like home, and this Southern squash casserole is one of them.

I can still picture my grandma in her kitchen, turning simple summer squash into a golden, bubbly masterpiece. It was her go-to for every family gathering, and the dish was always scraped clean.

Now, it’s my turn to make it. This yellow squash casserole is a warm hug on a plate. It’s creamy and cheesy and has the most amazing crunchy cracker topping. It’s the kind of comfort food that brings everyone to the table.

Why You’ll Love This Casserole?

It turns simple yellow squash into something truly amazing.
The creamy filling is cheesy, rich, and so comforting.
That buttery cracker topping gives it the perfect crunch.
This dish is a real crowd-pleaser at any potluck.
You can whip it up in a jiffy for dinner.

Ingredients You’ll Need

Salted butter: I always use salted butter to give this dish a rich, savory flavor from the start.
Yellow squash: This classic casserole calls for fresh yellow squash, which is the star of the show.
Sweet onion: I love Vidalia…it adds a wonderful, mild flavor that doesn’t overpower the delicate squash.
Kosher salt: This type of salt helps draw water out of the squash and seasons the dish perfectly.
Black pepper: A little fresh black pepper gives your casserole a gentle touch of warmth and spice.
Garlic powder: I find garlic powder adds a nice, savory depth that everyone seems to love.
Paprika: This adds a beautiful, warm color and a hint of sweet pepper flavor to the filling.
Large eggs: You’ll need eggs to bind all the creamy ingredients together and give the casserole structure.
Sour cream: I use full-fat sour cream because it makes the filling extra rich and tangy.
Mayonnaise: This is my secret weapon! It adds unbelievable creaminess and a subtle, savory taste.
Cheddar cheese: A good casserole is incomplete without cheese; sharp cheddar gives it the best flavor.
Ritz crackers: These buttery crackers create the most delicious, golden-brown, crunchy topping for your squash casserole.
Salted butter (melted): You will use more melted butter to mix with the crackers for that perfect topping.
Dried parsley: I sometimes sprinkle a little dried parsley on top for a pop of color.

How to Make Southern Squash Casserole?

Let’s make this amazing yellow squash casserole. It’s easier than you think and tastes just like home.

Step 1: First, cook the squash and season it. Melt butter in a skillet, add the squash and onion, and season with salt, pepper, garlic powder, and paprika. This usually takes about 8-10 minutes.

Step 2: Next, drain the cooked squash for about 5 minutes. Pour it into a colander and press down firmly to get rid of the excess water.

Step 3: Mix the creamy filling in a large bowl. Combine the beaten eggs, sour cream, and mayonnaise until smooth.

Step 4: Then, combine everything for the filling. Gently stir the drained squash mixture and one cup of the shredded cheese into the creamy base.

Step 5: It’s time to assemble and add the topping. Spread the filling into your baking dish, then sprinkle the buttery Ritz cracker topping over it.

Step 6: Finally, add the last of the cheese. Bake at 350°F for 25-30 minutes until the casserole is golden brown and bubbly hot.

Tips for the Best Yellow Squash Casserole

Want to knock it out of the park? Here are a few simple tricks I’ve learned over the years.

Really squeeze out all the water from your squash to avoid a soupy, wet casserole.
Grating your own cheddar cheese from a block will give you the best, meltiest results.
I always use a sweet Vidalia onion for the best flavor, but any sweet onion works.
Don’t overbake the casserole. You just want it heated through with a golden-brown top.
Let the casserole sit for a few minutes before you serve it. This helps it set up.

Variations and Substitutions

Feel free to get creative! This squash casserole recipe is very easy to change up to your liking.

You can use crushed butter crackers or panko breadcrumbs instead of Ritz for the topping.
Add some cooked, crumbled bacon or diced ham to the filling for a savory twist.
Feel free to use a different cheese, like Colby Jack, Monterey Jack, or even Gruyère.
Use Greek yogurt instead of sour cream for a lighter version with extra protein benefits.
Try adding other fresh herbs like chives or thyme to the squash filling for more flavor.

Make-Ahead and Storage Tips

To make ahead, you can assemble the entire casserole one day before you bake it.
Store leftovers in an airtight container in the fridge for up to 3 days.
To reheat, pop it in a 350°F oven until it is hot and bubbly again.
I don’t recommend freezing the casserole, as the texture can get a little watery.
You can prepare the topping separately and just add it right before you start baking.

What to Serve with Southern Squash Casserole?

This dish plays well with others! Here are some of my favorite things to serve alongside it.

Southern fried chicken: I love how the crispy chicken pairs with the creamy squash casserole. It’s a classic combo.
Baked Ham: The sweet and salty flavor of a baked ham is a perfect match for this cheesy side.
Grilled pork chops: Simple grilled pork chops let the flavors of your delicious squash casserole really shine through.

Frequently Asked Questions

This usually happens when the squash isn’t drained enough. You have to get in there and press out as much liquid as you can to get a creamy casserole.

No problem! You can use crushed cornflakes, panko breadcrumbs, or any other buttery cracker you have on hand. The goal is to get that crunch.

Yes, absolutely! A 9×9-inch square baking dish or any 2-quart casserole dish will work perfectly. You may just need to adjust the baking time by a few minutes.

Let the squash casserole cool completely. Then, cover the dish tightly or move the leftovers to an airtight container. It will keep well in the fridge for 3 days.

I love using a sharp knife or mandoline….Both help me easily slice it into uniform ¼-inch rounds carefully. This thickness is key to making sure your squash cooks perfectly and doesn’t turn mushy in the finished casserole.

A classic Southern squash casserole features tender yellow squash in a creamy, cheesy sauce topped with a buttery, crunchy cracker crumble. It is a perfect side dish for any meal, from weeknight dinners to holiday feasts.

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Prep Time 20

Cook Time 30

Total Time 50

Course Side Dish

Cuisine American

Servings 8

Calories 385 kcal

Ingredients

For the Casserole

2 pounds yellow squash (sliced ¼-inch thick)
1 large sweet onion (chopped)
2 tablespoons salted butter
1 teaspoon kosher salt
½ teaspoon black pepper
½ teaspoon garlic powder
¼ teaspoon paprika
2 large eggs (lightly beaten)
½ cup sour cream
½ cup mayonnaise
1 ½ cups shredded sharp cheddar cheese

For the Topping

1 sleeve Ritz crackers (about 35 crackers, crushed)
4 tablespoons salted butter (melted)
Dried parsley for garnish (optional)

Equipment

Large skillet
colander
Large Bowl
11×7-inch Baking Dish

Instructions

Prep the oven and dish: First, preheat your oven to 350°F and lightly grease an 11×7-inch baking dish.
Cook and season veggies for 8-10 minutes: In a large skillet, Melt 2 tbsp butter…. Then cook 2 lbs squash and chopped sweet onion with kosher salt, pepper, garlic powder, and paprika.
Drain for 5 minutes: Pour the seasoned squash into a colander. Press down firmly to squeeze out all excess water.
Make the creamy base: In a large bowl, whisk 2 eggs with ½ cup sour cream, and ½ cup mayo.
Combine the filling: Gently stir the well-drained squash and 1 cup of shredded cheddar cheese into the creamy base.
Assemble the casserole: Pour the filling into your prepared baking dish and spread it into an even layer.
Make the topping: In a small bowl, mix 1 sleeve of crushed Ritz crackers with 4 tbsp of melted butter.
Add the topping: Sprinkle the cracker mixture over the casserole.
Bake until golden: Bake at 350°F for 25-30 minutes until the casserole is bubbly and the top is golden brown.
Rest and serve: Let the finished casserole cool for 5-10 minutes before you serve it, garnished with dried parsley.

Notes

Squeezing the squash is the most important step for a creamy casserole.
For the best flavor and melt, I suggest grating your own cheese.
Don’t have a sweet onion? A regular yellow onion will work fine.
Let the casserole rest before serving so it can set up properly.
Store any leftovers you have in an airtight container in the fridge.
This casserole is a great side dish for holidays and potlucks.