Squash casserole is one of my favorite vegetarian side dishes to make for the holidays. This casserole is made with layers of yellow squash mixed with sour cream, mayonnaise, and eggs topped with cheese and crunchy butter crackers. It’s rich, creamy, cheesy, and so delicious! It feels super indulgent even though it’s vegetarian, so no one has to feel left out at the holidays.
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This yellow squash casserole is ridiculously delicious! I thought I wasn’t a fan of yellow squash until I tried this recipe. Sour cream and mayonnaise make the filling rich and creamy, and the squash has a great texture and nuttiness that goes so well with the buttery cracker topping. This casserole deserves a place on any holiday table.
What’s in This Squash Casserole Recipe?
- Butter: Unsalted butter makes the casserole moist and rich.
- Yellow Squash: Also known as summer squash, it has a mild nutty flavor. You’ll need 3 pounds or about 3 large squash. If using smaller squash, you’ll need 6. You can substitute half or all of the squash for zucchini if you prefer.
- Sweet Onion: Adds a touch of sweetness to the casserole.
- Eggs: Help bind the casserole and keep it moist.
- Sour Cream: Adds moisture and tanginess to the casserole.
- Mayonnaise: Helps keep the casserole moist and flavorful.
- Cheese: Sharp cheddar cheese adds savory flavor to the casserole and makes it gooey.
- Chives: Add a pop color and fresh onion flavor.
- Butter Crackers: Create a crispy topping for the casserole.
Tips for Success
- While the squash is cooking, stir it often to release steam and prevent browning.
- Cook the squash until tender but not mushy.
- It’s important to drain the squash after cooking to remove excess moisture.
- This casserole is easy to prep ahead of time. Assemble up to the point of adding the topping, but leave the topping off. Wrap the casserole and store it in the fridge for up to 24 hours. Let it come to room temperature for about 30 minutes before topping and baking according to the recipe.
- You can also freeze the unbaked casserole (without the topping) wrapped in 2 layers of plastic wrap and 1 layer of aluminum foil for up to 3 months. Let thaw overnight in the fridge before adding the topping and baking.
How to Store and Reheat
Store leftover squash casserole covered with aluminum foil in the refrigerator for up to 5 days or in the freezer for up to 3 months. Let thaw overnight in the refrigerator before reheating at 350°F for 25 minutes, or until warmed through.
Serving Suggestions
This yellow squash casserole is a true classic side dish that tastes delicious with just about any meal. It’s great with everything from crockpot chicken breast to pineapple ham. It’s a great Easter side dish, and I even love it at Thanksgiving, too.
Squash Casserole Recipe
Equipment
- 11×7-inch Baking Pan
Ingredients
- 6 tablespoons unsalted butter divided (¾ stick), plus more for greasing the pan
- 3 pounds yellow squash sliced ¼-inch thick
- 1 medium sweet onion chopped
- 2 teaspoons kosher salt divided
- 2 large eggs beaten
- 1 cup sour cream
- ½ cup mayonnaise
- 8 ounces freshly shredded sharp cheddar cheese divided
- 1 tablespoon chopped fresh chives plus more for garnish
- ½ teaspoon ground black pepper
- 2 sleeves round buttery crackers coarsely crushed
Instructions
- Preheat the oven to 350°F. Grease an 11×7-inch baking dish with butter.
- Melt 2 tablespoons of butter in a large skillet over medium heat. Once melted, stir in the squash, onion, and 1 teaspoon salt. Cook, stirring occasionally, until softened, about 8-10 minutes.6 tablespoons unsalted butter, 3 pounds yellow squash, 1 medium sweet onion, 2 teaspoons kosher salt
- Transfer the squash mixture to a colander set over the sink and let drain for 5 minutes.
- In a large bowl, mix the eggs, sour cream, mayonnaise, half the cheddar cheese, chives, remaining 1 teaspoon salt, and pepper.2 large eggs, 1 cup sour cream, ½ cup mayonnaise, 8 ounces freshly shredded sharp cheddar cheese, 1 tablespoon chopped fresh chives, ½ teaspoon ground black pepper
- Add the squash and gently fold to combine.
- Pour the squash mixture into the prepared pan. Top with the remaining cheddar cheese.
- In a medium bowl, melt the remaining 4 tablespoons butter. Stir in the crushed crackers. Sprinkle the crackers evenly over the top of the dish.2 sleeves round buttery crackers
- Bake for 20 minutes or until the filling is warmed through and the topping is golden brown. Let cool for 5 minutes, top with extra chives, if using, and serve.
Nutrition information is automatically calculated, so should only be used as an approximation.
Did you make this? Leave a comment!
How to Make Squash Casserole Step by Step
Cook the Squash: Preheat your oven to 350°F, grease an 11×7-inch baking dish with butter, and set aside. Melt 2 tablespoons of unsalted butter in a large skillet over medium heat. Once melted, stir in 3 pounds of sliced yellow squash, 1 chopped sweet onion, and 1 teaspoon of kosher salt. Cook, stirring occasionally, until softened, about 8-10 minutes.
Drain the Squash: Transfer the squash mixture to a colander set over the sink and let drain for 5 minutes.
Mix the Filling: In a large bowl, mix 2 large eggs, 1 cup of sour cream, ½ cup of mayonnaise, 4 ounces of shredded cheddar cheese, 1 tablespoon of chopped fresh chives, the remaining 1 teaspoon salt, and ½ teaspoon of ground black pepper. Add the squash and gently fold to combine.
Top with Cheese: Pour the squash mixture into the prepared pan. Top with the remaining 4 ounces of shredded cheddar cheese.
Sprinkle with Crackers: In a medium bowl, melt the remaining 4 tablespoons of unsalted butter. Stir in 2 sleeves of crushed round buttery crackers. Sprinkle the crackers evenly over the top of the dish.
Bake and Serve: Bake for 20 minutes or until the filling is warmed through and the topping is golden brown. Let cool for 5 minutes, top with extra chives, if using, and serve.
