Name: Yellow Squash Casserole
Prep time: 20 min
Cook time: 70 min
Total time: 90 min
Ingredients: 3 pounds yellow squash (sliced); 1 onion (chopped); 3 tablespoons olive oil; 1 teaspoon Kosher salt; ¾ teaspoon black pepper; 2 eggs; ½ cup mayonnaise; 8 ounces sour cream; 8 ounces Cheddar cheese (sharp); 1 tablespoon thyme (fresh); ¼ teaspoon cayenne pepper; 40 Ritz crackers (crushed); ¼ vegetarian Parmesan cheese; ½ cup butter

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For the perfect comforting fall meal, try this delicious crunchy squash casserole recipe! Our easy-to-follow recipe allows you to create a tasty, warm dish that the whole family will love. Packed with healthy ingredients and plenty of flavors, this savory casserole is sure to be a hit. Plus, it’s a great way to use up leftover summer squash from your garden or local farmer’s market. So go ahead and give it a try – you won’t regret it!

A close-up of a spoon scooping out a portion of golden, crumbly squash casserole from a baking dish. — Yellow Squash Casserole. Photo Credit: Splash of Taste

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Why You’ll Love This Easy Squash Casserole Recipe

Comfort Food Appeal: Squash casserole hits all the notes of homestyle comfort, making it a go-to dish for cozy evenings.
Seasonal Ingredients: The recipe celebrates seasonal squash, making it an excellent choice for farm-to-table enthusiasts.
Nutrient-Rich: Squash is packed with essential nutrients like fiber, vitamins, and minerals, adding a healthy twist to your meal.
Easy to Prep: No fancy culinary skills are needed here. A squash casserole is simple enough for even novice cooks to tackle.
Make-Ahead Magic: The recipe is perfect for prepping ahead of time, freeing you up to focus on other elements of your meal.
Crowd-Pleaser: The creamy, savory, and slightly sweet profile of squash casserole makes it a hit at family gatherings and potlucks.
Freezer-Friendly: Made too much? No problem. Squash casserole freezes well, making it a convenient option for future meals.

Ingredients You’ll Need

You’ll need all the ingredients shown in the photograph below.

Various labeled ingredients for a recipe are arranged on a white surface, including squash, cheddar, eggs, mayonnaise, sour cream, and spices—perfect for preparing a classic squash casserole. — Yellow Squash Casserole Ingredients. Photo Credit: Splash of Taste

The most delicious squash filling topped by an insanely good buttery cracker topping, this is a family favorite that you don’t want to miss out on!

How To Make Squash Casserole With Step-By-Step Instructions

It’s easy to make our squash casserole with Ritz crackers and mayonnaise if you follow our simple instructions.

A full printable recipe and the measurements in both US customary and metric are available in the recipe card below.

Preheat your oven to 350°F/180°C.

Add the yellow squash to a rimmed baking sheet, along with onion, olive oil, salt, and pepper, and toss to combine. Cook until tender, approximately 20 – 25 minutes.

The cooked squash will release liquid, so completely drain it in a colander, you don’t want a watery casserole, and then set it aside to cool slightly.

Grease an 11 x 7-inch casserole dish.

In a large bowl, whisk eggs, then add mayonnaise, sour cream, sharp cheddar cheese, fresh thyme, and cayenne pepper, and then gently fold in the cooled squash mixture.

Now add it to your prepared baking dish and cook until softened for approximately 20 minutes.

Squash mixture in a casserole dish. — Whisk the eggs, then add the mayo, sour cream, cheese, thyme, and cayenne. Fold in the cooled squash. Transfer the mixture to an ovenproof dish and bake for 20 minutes, or until set and softened.

Meanwhile, in a smaller bowl, add crushed Ritz crackers and vegetarian Parmesan cheese, pour in melted butter, and stir to combine.

Now sprinkle the Ritz cracker crumbs mixture evenly over the top of your cooked squash.

Cook for a further 25 – 30 minutes until your cooked squash casserole top is golden brown and the cheese is melted and bubbly.

An oval white baking dish of squash casserole with a golden brown crumb topping sits on a wooden cutting board; a hand holds a nearby cloth. Three forks and a plate are in the background. — Place the mixture in an ovenproof dish and bake 20 minutes until softened.

Allow 2 – 3 minutes to cool, and then serve.

Enjoy your hearty vegetarian squash casserole!

A helping of squash casserole on a serving spoon.

Yellow Squash Casserole

I make this Yellow Squash Casserole whenever I need something that feels genuinely comforting without a lot of fuss. It starts with roasted yellow squash and onion folded into a creamy mixture of sharp cheddar, sour cream, and mayo with a hint of fresh thyme and just enough cayenne to keep things interesting. The whole thing gets topped with a buttery crushed Ritz cracker and Parmesan crust that bakes up golden and crunchy while the filling stays rich and bubbly underneath. It works beautifully as a vegetarian main or a standout side dish for any gathering.

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Prep Time: 20

Cook Time: 1 10

Total Time: 1 30

Course: Casserole, Dinner, Main course, Side Dish

Cuisine: American, Southern

Servings:

Calories: 540kcal

Author: Mandy Applegate

Equipment

Ingredients

3 pounds yellow squash sliced
1 onion chopped
3 tablespoons olive oil
1 teaspoon Kosher salt
¾ teaspoon black pepper
2 eggs
½ cup mayonnaise
8 ounces sour cream
8 ounces Cheddar cheese sharp
1 tablespoon thyme fresh
¼ teaspoon cayenne pepper
40 Ritz crackers crushed
¼ vegetarian Parmesan cheese
½ cup butter

Metric – US Customary

Video

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Instructions

Pre heat your oven to 350°F (180°C).
In a large rimmed baking sheet add the squash, onion, olive oil, salt, black pepper and toss to combine. Cook until tender for approximately 20-25 minutes. Completely drain the squash mixture and set aside to cool slightly.
3 pounds yellow squash, 1 onion, 3 tablespoons olive oil, 1 teaspoon Kosher salt, ¾ teaspoon black pepper
In a large bowl whisk the eggs, then add mayonnaise, sour cream, cheddar cheese, thyme and cayenne pepper and gently fold in the cooled squash mixture. Now add it into your prepared casserole dish and cook until softened for approx. 20 minutes.
2 eggs, ½ cup mayonnaise, 8 ounces sour cream, 8 ounces Cheddar cheese, 1 tablespoon thyme, ¼ teaspoon cayenne pepper
Meanwhile, in a smaller bowl add the crushed Ritz cracker crumbs, vegetarian parmesan cheese and pour in the melted butter. Now sprinkle the Ritz cracker crumbs over the top of your cooked squash mixture.
40 Ritz crackers, ¼ vegetarian Parmesan cheese, ½ cup butter
Cook for a further 25-30 minutes until the top is golden brown and the cheese is melted and bubbly. Allow to cool for 2-3 minutes, then serve. Enjoy your hearty squash casserole!

Notes

Here are a few tips I’ve picked up from making this casserole more than once:

Drain the squash thoroughly: After roasting, press the squash mixture in a colander or pat it with paper towels to remove as much liquid as possible before folding it into the creamy filling. Excess moisture is the main reason casseroles turn out watery.

Let the squash cool before mixing: Folding hot squash directly into the egg mixture can cause the eggs to begin cooking too early. Give the roasted squash at least 10 minutes to cool slightly before combining everything in the bowl.

Use freshly shredded cheddar: Pre-shredded cheese is coated in starches that prevent it from melting as smoothly. Shredding sharp cheddar straight from the block gives you a creamier, silkier filling.

Gently fold, don’t stir: When combining the squash into the egg and cheese mixture, use a gentle folding motion rather than vigorous stirring so the filling stays light and the squash holds its shape.

Add the topping after the first bake: Sprinkling the Ritz cracker mixture onto the fully baked filling rather than at the beginning keeps the crust from getting soggy. The second round of baking, 25 to 30 minutes, is what gives you that deep golden, crunchy finish.

Store properly: Once cooled, chill the casserole covered or in airtight containers for up to 3 days. To freeze, skip the cracker topping, wrap portions in plastic wrap and foil, then freeze in freezer containers for up to 3 months. Once thawed, add the toppings fresh and reheat.

Nutrition

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Recipe Notes and Expert Tips

Choose the Right Squash: Opt for fresh, firm squash with vibrant color for the best flavor and texture.
Precook the Squash: Boil or steam the squash until it’s just tender to ensure it cooks evenly in the casserole.
Season Generously: Don’t skimp on the salt, pepper, and spices. Seasoning the squash beforehand brings out its natural flavors.
Preheat the Oven: Always preheat your oven for consistent cooking results.
Check for Doneness: Use a fork to test if the casserole is cooked through. The squash should be tender but not mushy.
Rest Before Serving: Letting the casserole sit for a few minutes after baking helps the flavors meld and makes it easier to serve.
Learn how to grill squash

How To Store Leftover Squash Casserole

Store covered in the fridge for up to 3 days.

And if you have leftover squash, try this leek and squash quiche.

There are so many different ways you can cook squash, so if you’re a squash lover, then why not try spaghetti squash salad or try this delicious twice baked spaghetti squash.

Can you make squash casserole ahead?

Yes, you can; you can make it the day before, cover and refrigerate. Just reheat it when you are ready to eat it.

Can you freeze squash casserole?

Yes, you can! Wrap it up and freeze your cooked squash casserole, but don’t add the Ritz crackers, as they will go soggy upon thawing.

Freeze for up to 3 months; when ready to use it, add additional cooking time.

More Easy Casserole Recipes for You To Try at Home

If you loved this fabulous yellow squash casserole recipe, then why not try these?

Yellow Squash Casserole Recipe