This Squash Casserole Recipe turns humble summer squash into the creamiest, cheesiest side dish on the table.
It’s the one dish that disappears first at potlucks and Sunday dinners alike.
Tender squash gets folded into a rich sour cream and cheddar mixture, then topped with buttery cracker crumbs that turn golden in the oven.
Every bite is soft on the inside with just enough crunch on top to keep things interesting.
I grew up eating a version of this at almost every family gathering, and it never once got skipped for seconds.
Once you try this recipe, you’ll understand why squash casserole shows up on Southern tables year after year.
| Quick Recipe Summary | |
|---|---|
| Prep Time | 20 minutes |
| Cook Time | 35 minutes |
| Total Time | 55 minutes |
| Servings | 8 servings |
| Difficulty Level | Easy |
Why You’ll Love This Squash Casserole Recipe
This dish hits that sweet spot between comfort food and something you’d actually serve for a holiday meal.
It comes together with basic ingredients, most of which you probably already have on hand.
It also happens to be one of those recipes that tastes even better the next day, which makes it a great make ahead option for busy weeks.
If you’re planning a full spread, it holds its own right alongside a green bean casserole without competing for attention.
- Comes together with pantry staples and one skillet
- Creamy, cheesy texture with a crisp, buttery topping
- Great way to use up a glut of summer squash
- Reheats beautifully, so leftovers are never a letdown
- Flexible enough for weeknight dinners or holiday tables
Ingredients
You only need a handful of ingredients for this casserole, and most of them are things you’ll already have in the fridge or pantry.
The star, of course, is fresh yellow squash.
- 2 1/2 pounds yellow squash, sliced into 1/4 inch rounds
- 1 medium yellow onion, chopped
- 4 tablespoons unsalted butter, divided
- 1/2 cup sour cream
- 1/4 cup mayonnaise
- 1 large egg, beaten
- 1 1/2 cups shredded sharp cheddar cheese, divided
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1/2 teaspoon garlic powder
- 1 sleeve (about 35) Ritz crackers, crushed
- Cooking spray, for the baking dish
Another favorite of mine when I want a bit more texture in the topping: broccoli cheese casserole, which uses a similar cracker crumb finish.
Kitchen Equipment Needed
Nothing fancy is required here, just a few basics that make the process smoother. A good skillet and a sturdy baking dish are really all you need.
- Large cast iron skillet or heavy bottomed saute pan
- 9×13 inch baking dish
- Mixing bowls
- Box grater, if shredding cheese fresh
- Fine mesh strainer or colander, for draining the squash
- Measuring cups and spoons
- Wooden spoon or spatula
Read Also: Scalloped Potatoes Recipe
Recommended Products for This Recipe
These are a few products I personally reach for whenever I make this casserole.
None of them are required, but each one makes the process a little easier or the results a little better.
1. Lodge Cast Iron Skillet
A heavy cast iron skillet heats evenly, which means the squash and onions cook down at the same rate without scorching in spots.
It also holds heat well if you want to keep things warm while you finish the rest of the casserole.
2. Pyrex 9×13 Baking Dish
A glass baking dish lets you see the bottom edges browning, so you know exactly when the casserole is done.
It also goes straight from oven to table, which cuts down on dishes.
3. Sharp Aged Cheddar Cheese Block
Shredding your own cheese from a block instead of using pre-shredded bags gives you a smoother, creamier melt.
Pre-shredded cheese is coated in anti-caking agents that can leave the casserole slightly grainy.
4. OXO Salad Spinner
I use mine as an extra step after draining the squash in a colander, since it spins off even more liquid.
Less liquid in the squash means a firmer, less watery casserole once it bakes.
This pairs well with a side of honey glazed carrots if you want to round out the meal with something a little sweeter.
Step-by-Step Instructions: How to Make Squash Casserole
1. Prep the oven and baking dish
- Preheat your oven to 350 degrees Fahrenheit.
- Lightly coat a 9×13 inch baking dish with cooking spray and set it aside.
- Slice the yellow squash into rounds about 1/4 inch thick and chop the onion. Set both aside so they are ready to go straight into the skillet.
2. Cook the squash and onion
- Melt 2 tablespoons of the butter in a large skillet over medium heat.
- Add the sliced squash and chopped onion to the skillet.
- Cook, stirring occasionally, for 8 to 10 minutes, until the squash is tender and the onion turns translucent.
- Remove the skillet from the heat and pour the squash mixture into a strainer set over the sink or a bowl.
- Let the squash drain for about 5 minutes, then gently press out any extra liquid with the back of a spoon or a clean paper towel. This step keeps the finished casserole from turning watery.
3. Mix the creamy base
- In a large mixing bowl, whisk together the sour cream, mayonnaise, and beaten egg until smooth.
- Stir in 1 cup of the shredded cheddar cheese, the salt, black pepper, and garlic powder.
- Mix until everything is evenly combined.
4. Combine the squash with the base
- Add the drained squash and onion mixture to the bowl with the creamy base.
- Stir gently until the squash is fully coated. Try not to overmix, since you want to keep some texture from the squash rather than mashing it down.
5. Assemble the casserole
- Pour the squash mixture into your prepared 9×13 inch baking dish and spread it into an even layer.
- Sprinkle the remaining 1/2 cup of shredded cheddar cheese evenly over the top.
6. Make the cracker topping
- Melt the remaining 2 tablespoons of butter in a small bowl or in the microwave.
- Crush the Ritz crackers into coarse crumbs, either by hand in a zip top bag or with a rolling pin.
- Stir the melted butter into the crushed crackers until the crumbs are evenly moistened.
- Sprinkle the buttery cracker mixture evenly over the top of the casserole, covering the cheese layer.
7. Bake the casserole
- Place the baking dish in the preheated oven.
- Bake for 30 to 35 minutes, until the topping is golden brown and the casserole is bubbling around the edges.
- Remove from the oven and let it rest for 5 to 10 minutes before serving. This short rest helps the casserole set up so it holds together when you scoop it.
If you want another baked side that uses a similar cracker topping technique, my roasted Brussels sprouts are worth trying too.
Tips for The Best Squash Casserole
A few small details make a big difference in how this casserole turns out. Most of them come down to controlling moisture and not rushing the prep.
- Choose smaller, firmer squash, since larger ones tend to be more watery and seedy
- Don’t skip draining the squash after cooking, or the casserole can turn soggy
- Shred your own cheese from a block for a smoother melt
- Let the casserole rest before serving so it holds its shape when scooped
- Taste the squash mixture before baking and adjust salt and pepper as needed
You might also enjoy: Garlic Parmesan Mashed Cauliflower
Serving Suggestions
Squash casserole is a side dish through and through, so it plays nicely with almost any main course.
It’s especially popular around the holidays, but it works just as well on a random Tuesday.
I like to serve it alongside roasted meats or something with a bit of char to balance out the richness. A simple green vegetable on the side rounds things out nicely.
- Roasted or grilled chicken
- Honey baked ham for holiday spreads
- Sauteed Green Beans with Garlic for a lighter vegetable side
- Cornbread or dinner rolls to soak up any extra sauce
- A simple green salad to cut through the richness
Variations of Squash Casserole
This recipe is easy to adjust depending on what you have on hand or what your family prefers.
None of these swaps change the overall method much.
- Swap half the yellow squash for zucchini for a slightly different flavor and color
- Use panko breadcrumbs instead of crushed crackers for a lighter, crisper topping
- Add a pinch of cayenne pepper for a little heat
- Stir in cooked, crumbled bacon for extra richness
- Use pepper jack instead of cheddar for a milder kick of spice
For another vegetable side that takes well to swaps and add-ins, take a look at my garlic mashed potatoes.
Storage and Reheating
This casserole keeps well in the fridge, which makes it a solid make ahead option for busy weeks or holiday planning.
Reheating it is simple and doesn’t dry it out if you do it gently.
- Store leftovers in an airtight container in the refrigerator for up to 4 days
- Reheat individual portions in the microwave in 30 second bursts until warmed through
- Reheat larger portions in a 300 degree oven, covered with foil, for about 15 minutes
- Freezing is not recommended, since the creamy base can separate and turn watery once thawed
Another dish that reheats just as well the next day is my sweet potato casserole with marshmallows, which is worth keeping in your back pocket for holiday meal prep.
Nutritional Facts
These numbers are estimates based on one serving out of eight and will vary depending on the exact ingredients you use.
| Nutrition (per serving) | |
|---|---|
| Calories | 285 kcal |
| Total Fat | 21g |
| Saturated Fat | 10g |
| Carbohydrates | 14g |
| Fiber | 2g |
| Sugar | 6g |
| Protein | 9g |
| Sodium | 470mg |
For a lighter option that pairs well with a dish like this, check out my herb roasted vegetables.
Health Benefits of Key Ingredients
While this is very much a comfort food side dish, a few of the ingredients bring some genuine nutritional value to the table. Squash in particular is worth highlighting.
- Yellow squash is a good source of vitamin C and provides fiber with very few calories
- Onions contain antioxidants and compounds linked to heart health
- Eggs contribute protein and several important vitamins
- Cheddar cheese adds calcium and additional protein to the dish
Another squash-forward recipe I love for similar reasons is my corn casserole, which brings its own mix of fiber and nutrients to the table.
FAQs About Squash Casserole
1. Can I make squash casserole ahead of time?
Yes, you can assemble the casserole up to a day in advance and refrigerate it, covered, before baking.
Add the cracker topping right before it goes in the oven so it stays crisp.
2. Can I use frozen squash instead of fresh?
Frozen squash works in a pinch, but it holds more water than fresh squash.
Thaw it fully and press out as much liquid as possible before using it in the recipe.
3. Why did my squash casserole turn out watery?
This usually happens when the squash isn’t drained well enough after cooking.
Squash releases a lot of moisture as it sits, so draining and gently pressing it is an important step, not an optional one.
4. Can I freeze squash casserole?
Freezing isn’t ideal, since the sour cream and mayonnaise base tends to separate once thawed.
It’s best enjoyed fresh or as refrigerated leftovers within a few days.
5. What can I use instead of Ritz crackers for the topping?
Panko breadcrumbs, crushed saltines, or crushed cornflakes all work well as substitutes.
Just toss whichever one you choose with melted butter before sprinkling it on top.
Read Also: Broccoli Cheese Casserole Recipe
Squash Casserole
Ingredients
- 2 1/2 pounds yellow squash about 1.13 kg, sliced into 1/4 inch rounds
- 1 medium yellow onion chopped
- 4 tablespoons unsalted butter 56g, divided
- 1/2 cup sour cream 120ml
- 1/4 cup mayonnaise 60ml
- 1 large egg beaten
- 1 1/2 cups sharp cheddar cheese 170g, shredded, divided
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1/2 teaspoon garlic powder
- 1 sleeve Ritz crackers about 35 crackers, crushed
- Cooking spray for the baking dish
Equipment
- Large cast iron skillet or heavy bottomed saute pan
- 9×13-inch baking dish glass recommended to see browning edges
- Mixing bowls
- Box grater if shredding cheese fresh
- Fine mesh strainer or colander for draining the squash
- Measuring cups and spoons
- Wooden spoon or spatula
- OXO Salad Spinner (optional) for spinning off extra liquid
Method
- Preheat oven to 350°F. Lightly coat a 9×13 inch baking dish with cooking spray. Slice squash into 1/4 inch rounds and chop the onion.
- Melt 2 tablespoons butter in a large skillet over medium heat. Add squash and onion and cook, stirring occasionally, for 8-10 minutes until tender and translucent.
- Pour the squash mixture into a strainer set over a bowl or sink. Drain for 5 minutes, then gently press out extra liquid with a spoon or paper towel to prevent a watery casserole.
- In a large mixing bowl, whisk together sour cream, mayonnaise, and beaten egg until smooth. Stir in 1 cup of cheddar cheese, salt, pepper, and garlic powder until evenly combined.
- Add the drained squash and onion to the creamy mixture and stir gently until fully coated, keeping some squash texture intact.
- Pour the squash mixture into the prepared baking dish and spread into an even layer. Sprinkle the remaining 1/2 cup of cheddar cheese evenly over the top.
- Melt the remaining 2 tablespoons of butter. Crush the Ritz crackers into coarse crumbs, then stir in the melted butter until evenly moistened. Sprinkle the buttery crumbs over the cheese layer.
- Bake for 30-35 minutes until the topping is golden brown and the casserole is bubbling around the edges. Let rest for 5-10 minutes before serving to help it set up.
Nutrition
Notes
- Choose smaller, firmer squash for best results as larger ones tend to be more watery and seedy.
- Don’t skip draining the squash after cooking, or the casserole can turn out soggy.
- Shred your own cheese from a block for a smoother, creamier melt; pre-shredded cheese has anti-caking agents that can leave the casserole grainy.
- Let the casserole rest before serving so it holds its shape when scooped.
- Taste the squash mixture before baking and adjust salt and pepper as needed.
- You can assemble the casserole up to a day in advance and refrigerate it, covered. Add the cracker topping right before baking for the crispiest finish.
- Store leftovers in an airtight container in the refrigerator for up to 4 days.
- Freezing is not recommended, as the sour cream and mayonnaise base can separate and turn watery once thawed.
- Swap half the yellow squash for zucchini for a slightly different flavor and color.
- Use panko breadcrumbs, crushed saltines, or crushed cornflakes instead of Ritz crackers for a different topping texture.
Private Notes
Tried this recipe?
Let us know how it was!Conclusion
Squash casserole is one of those recipes that earns its spot on the table again and again.
It’s simple, comforting, and always seems to disappear faster than anything else in the spread.
Give this recipe a try the next time you have a pile of fresh squash on hand or a holiday meal to plan.
I would love to hear how it turned out for you, so drop a comment below or share a photo if you make it.
Recommended:
- Cheesy Au Gratin Potatoes Recipe
- Scalloped Potatoes Recipe
- Spinach and Mushroom Casserole Recipe
- Baked Acorn Squash Recipe
- Carrot Souffle Casserole
