This zucchini and squash casserole recipe is the kind of side dish that disappears from the table before anything else does.
Tender rounds of zucchini and yellow squash get folded into a creamy, cheesy mixture and baked under a buttery cracker crumb topping until golden and bubbly.
It is the classic Southern squash casserole that shows up at potlucks, Sunday dinners, and holiday tables, and it takes barely 20 minutes of prep to get it into the oven.
If you have grown up eating this dish, this version will feel like home, and if you are new to it, get ready for a new favorite.
| Quick Recipe Summary | |
|---|---|
| Prep Time | 20 minutes |
| Cook Time | 35 minutes |
| Total Time | 55 minutes |
| Servings | 8 servings |
| Difficulty Level | Easy |
This Squash Casserole Recipe shares that same comforting spirit, so if you love one you will want to bookmark both.
Why You’ll Love This Zucchini and Squash Casserole Recipe
This casserole is proof that a handful of simple ingredients can turn into something people ask for by name.
It comes together with pantry staples and whatever squash you have on hand, and it always tastes like more effort went into it than actually did.
It is endlessly flexible too. You can dress it up for a holiday spread or keep it simple for a weeknight, and it holds up beautifully as leftovers the next day.
- Uses up an abundance of summer zucchini and yellow squash
- Creamy, cheesy filling with a crunchy buttery topping
- Ready in under an hour with minimal hands-on effort
- A crowd-pleasing side dish for potlucks, cookouts, and holidays
- Easy to prep ahead and bake later
Another one my family keeps requesting is this Zucchini Fritters Recipe, especially when we are trying to use up an extra-large squash harvest.
Ingredients
Everything here is easy to find at any grocery store, and most of it you probably already have in the fridge.
The full measurements are listed in the recipe card below.
- 2 pounds zucchini and yellow squash, sliced into 1/4 inch rounds
- 1 teaspoon salt, for drawing out moisture
- 4 tablespoons unsalted butter, divided
- 1 medium yellow onion, chopped
- 2 cloves garlic, minced
- 1 cup sour cream
- 2 large eggs, beaten
- 2 cups shredded sharp cheddar cheese, divided
- 1/2 cup grated parmesan cheese
- 1/4 teaspoon black pepper
- 1/4 teaspoon paprika
- 1 1/2 cups crushed Ritz crackers
- 2 tablespoons butter, melted, for the topping
Great, this pairs really well with the topping I use on my Cheesy Au Gratin Potatoes Recipe if you want to try a similar buttery crunch on another side dish.
Kitchen Equipment Needed
Nothing fancy is required here, but a few tools make the prep faster and the results more consistent.
- 9×13 inch baking dish
- Large cast iron skillet or nonstick pan
- Sharp knife or mandoline slicer
- Box grater, if shredding your own cheese
- Colander
- Mixing bowls
- Measuring cups and spoons
Read Also: Scalloped Potatoes Recipe
Recommended Products for This Recipe
These are a few products I personally use in my own kitchen that make this casserole even easier and more consistent.
I am not the type to recommend gadgets I do not actually reach for, so these have all earned a spot in my regular rotation.
The same buttery crumb topping trick shows up in my Cheesy Hashbrown Casserole Recipe, so these tools pull double duty in my kitchen.
1. OXO Mandoline Slicer
Getting the squash and zucchini into even, thin slices is the single biggest factor in how well this casserole cooks through.
This slicer makes quick work of it and keeps every piece the same thickness, so nothing turns mushy while other pieces are still firm.
2. Lodge Cast Iron Skillet
I sauté the onion and garlic in cast iron because it holds heat so evenly and gives the onions a deeper flavor than a thin nonstick pan does.
It is also the kind of pan that will last decades if you take care of it.
3. Emile Henry Ceramic Baking Dish
A heavier baking dish like this one distributes heat more gently than thin metal pans, which keeps the edges of the casserole from drying out before the center is done.
It also goes straight from the oven to the table and looks great doing it.
4. Cabot Sharp Cheddar Cheese
A good sharp cheddar makes a noticeable difference in the final flavor of this casserole.
I always reach for a block I can shred myself instead of pre-shredded bags, since it melts smoother and tastes far more pronounced.
5. Ritz Original Crackers
These are the classic topping for a reason. The buttery flavor and light crunch hold up perfectly against the creamy squash underneath, and they toast to a beautiful golden color in the oven.
Step-by-Step Instructions: How to Make Zucchini and Squash Casserole
1. Prep the Squash
- Preheat your oven to 350°F and lightly grease a 9×13 inch baking dish.
- Slice the zucchini and yellow squash into 1/4 inch thick rounds using a sharp knife or a mandoline slicer for even pieces.
- Place the sliced squash in a colander set over a bowl or in the sink, sprinkle with 1 teaspoon of salt, and toss gently to coat.
- Let the squash sit for 10 to 15 minutes so the salt can draw out excess moisture.
- Pat the slices dry thoroughly with paper towels, since any leftover moisture can make the casserole watery.
2. Sauté the Aromatics and Squash
- Melt 2 tablespoons of the butter in a large skillet over medium heat.
- Add the chopped onion and cook for 3 to 4 minutes, stirring occasionally, until softened and lightly golden.
- Stir in the minced garlic and cook for another 30 seconds until fragrant.
- Add the dried squash and zucchini slices to the skillet and cook for 5 to 6 minutes, stirring occasionally, until just barely tender but not mushy.
- Remove the skillet from the heat and let the mixture cool for a few minutes.
3. Mix the Creamy Filling
- In a large mixing bowl, whisk together the sour cream, beaten eggs, black pepper, and paprika until smooth.
- Fold in 1 1/2 cups of the shredded cheddar cheese and the grated parmesan cheese.
- Add the slightly cooled squash and onion mixture to the bowl.
- Gently fold everything together until the squash is evenly coated in the creamy mixture.
4. Assemble the Casserole
- Pour the squash mixture into the 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.
- In a small bowl, toss the crushed Ritz crackers with the remaining 2 tablespoons of melted butter until evenly coated.
- Scatter the buttered cracker crumbs evenly over the cheese layer.
5. Bake and Rest
- Bake the casserole uncovered for 30 to 35 minutes, until the center is set and the top is golden brown.
- If the topping browns too quickly, loosely tent the dish with aluminum foil for the remaining bake time.
- Remove the casserole from the oven and let it rest for 10 minutes before serving, so it has time to set up.
- Serve warm straight from the baking dish.
The technique of drawing moisture out with salt before cooking is one I lean on constantly, and it works just as well in my Green Bean Casserole Recipe.
Tips for The Best Zucchini and Squash Casserole
A few small details make the difference between a watery casserole and one with a firm, creamy texture that holds its shape when you scoop it.
- Do not skip salting and drying the squash, since this step prevents excess water from pooling in the dish
- Slice the squash evenly so every piece cooks at the same rate
- Use freshly shredded cheese rather than pre-shredded bags for a smoother melt
- Do not overcook the squash in the skillet, since it will continue cooking in the oven
- Let the casserole rest before serving so it firms up and slices cleanly
You might also enjoy: Corn Casserole Recipe
Serving Suggestions
This casserole is a natural fit for just about any main course, especially the kind of comfort food dinners that call for a hearty vegetable side.
It is rich enough to balance out simpler proteins and light enough to sit alongside something more indulgent.
A sprinkle of fresh chives or chopped parsley over the top right before serving adds a nice pop of color and freshness.
- Serve alongside roasted or grilled chicken for a classic Sunday dinner
- Pair with baked ham for a holiday table spread
- Add a slice of cornbread to round out a Southern-style meal
- Serve with grilled pork chops for an easy summer dinner
- Bring it to a potluck alongside other baked casseroles
This dish also makes a wonderful pairing with Roast Chicken with Potatoes when you want a complete, comforting dinner.
Variations of Zucchini and Squash Casserole
Once you have made this recipe a time or two, it is easy to start adjusting it to whatever you have on hand or whatever flavor direction you are craving that day.
- Swap the cheddar for pepper jack cheese for a little heat
- Use crushed panko breadcrumbs instead of crackers for an extra crisp topping
- Stir in cooked, crumbled bacon for a smoky, savory version
- Add a cup of fresh or frozen corn kernels for sweetness and texture
- Mix in fresh basil or thyme for an herby, garden-inspired twist
If you love casserole variations, this Broccoli Cheese Casserole Recipe is another one worth trying for a different vegetable base.
Storage and Reheating
This casserole stores well, which makes it a great make-ahead option for busy weeks or holiday planning.
- Refrigerate leftovers in an airtight container for up to 4 days
- Reheat individual portions in the microwave for 1 to 2 minutes until warmed through
- Reheat the full dish covered in a 350°F oven for about 15 minutes
- Freezing is not recommended, since the texture of the squash becomes watery after thawing
- You can assemble the casserole up to a day ahead, cover, and refrigerate before baking
The same make-ahead approach works nicely for a busy weeknight side like Herb Roasted Vegetables.
Nutritional Facts
| Nutrition Per Serving | |
|---|---|
| Calories | 295 kcal |
| Carbohydrates | 13g |
| Protein | 11g |
| Fat | 23g |
| Saturated Fat | 13g |
| Cholesterol | 95mg |
| Sodium | 480mg |
| Fiber | 2g |
| Sugar | 5g |
Nutritional values are estimates based on standard ingredients and can vary depending on brands used.
This pairs nicely in a meal plan alongside lighter mains like my Garlic Parmesan Mashed Cauliflower if you are watching overall carbs for the meal.
Health Benefits of Key Ingredients
Beyond how good it tastes, this casserole actually brings some real nutritional value to the table thanks to the vegetables at its base.
Zucchini and yellow squash are both low in calories while offering a good amount of vitamins and minerals.
Combined with the protein from the eggs and cheese, this dish offers more balance than most people expect from a creamy baked side.
- Zucchini is high in vitamin C and supports immune health
- Yellow squash provides potassium, which supports healthy blood pressure
- Eggs contribute protein and choline for muscle and brain health
- Garlic and onion offer antioxidants that support heart health
- Cheese provides calcium and protein to help balance the dish
For another vegetable-forward main, my Salmon with Roasted Vegetables is a great option to keep the health benefits going through the whole meal.
FAQs About Zucchini and Squash Casserole
1. Can I make this casserole ahead of time?
Yes, you can assemble the entire casserole up to a day in advance. Just cover it tightly and refrigerate, then bake it fresh when you are ready to serve.
2. Why is my squash casserole watery?
This usually happens when the squash is not salted and dried thoroughly before cooking.
Take the time to let the salted squash sit and pat it dry, since this step removes the excess moisture that causes a soggy casserole.
3. Can I use only zucchini or only yellow squash?
Absolutely, either vegetable works well on its own if that is what you have available. Using both simply adds a bit of color and slight variation in texture.
4. What can I use instead of Ritz crackers?
Panko breadcrumbs, crushed saltine crackers, or even crushed cornflakes all work well as a substitute.
Just be sure to toss them with melted butter so they crisp up nicely in the oven.
5. Is this recipe gluten free?
It is not as written, since the crackers contain gluten. You can easily make it gluten free by swapping in gluten free crackers or gluten free panko breadcrumbs.
Another popular pairing here is Garlic Butter Shrimp with Veggies if you want a lighter seafood dinner alongside this casserole.
Zucchini and Squash Casserole
Ingredients
- 2 pounds zucchini and yellow squash about 900g total, sliced into 1/4 inch rounds
- 1 teaspoon salt for drawing out moisture
- 4 tablespoons unsalted butter 56g, divided (2 tbsp for sautéing, 2 tbsp for topping)
- 1 medium yellow onion about 1 cup or 150g, chopped
- 2 cloves garlic minced
- 1 cup sour cream 240g
- 2 large eggs beaten
- 2 cups sharp cheddar cheese 8 oz or 225g, shredded, divided (1 1/2 cups for filling, 1/2 cup for topping)
- 1/2 cup parmesan cheese 2 oz or 55g, grated
- 1/4 teaspoon black pepper
- 1/4 teaspoon paprika
- 1 1/2 cups Ritz crackers about 40 crackers, crushed
Equipment
- 9×13-inch baking dish heavy ceramic recommended for even heat distribution
- Large cast iron skillet or nonstick pan for sautéing
- Mandoline slicer optional, for even 1/4-inch slices
- Sharp knife if not using mandoline
- Box grater for shredding cheese from a block
- Colander for draining excess moisture from squash
- Mixing bowls
- Measuring cups and spoons
Method
- Preheat oven to 350°F and lightly grease a 9×13 inch baking dish. Slice squash into 1/4 inch thick rounds.
- Place sliced squash in a colander, sprinkle with 1 teaspoon salt, and toss. Let sit 10-15 minutes, then pat dry thoroughly with paper towels.
- Melt 2 tablespoons butter in a large skillet over medium heat. Add onion and cook 3-4 minutes until softened. Stir in garlic and cook 30 seconds until fragrant.
- Add dried squash to the skillet and cook 5-6 minutes until just barely tender. Remove from heat and cool slightly.
- In a large bowl, whisk together sour cream, beaten eggs, pepper, and paprika until smooth. Fold in 1 1/2 cups cheddar and the parmesan.
- Add the cooled squash mixture to the bowl and gently fold until evenly coated in the creamy mixture.
- Pour into the prepared baking dish and spread evenly. Sprinkle remaining 1/2 cup cheddar over the top.
- Toss crushed Ritz crackers with remaining 2 tablespoons melted butter. Scatter buttered crumbs evenly over the cheese layer.
- Bake uncovered 30-35 minutes until center is set and topping is golden brown. Tent with foil if topping browns too quickly.
- Let rest 10 minutes before serving to allow the casserole to set up. Serve warm.
Nutrition
Notes
- Do not skip salting and drying the squash — this step prevents excess water from making the casserole watery.
- Slice the squash evenly so every piece cooks at the same rate. A mandoline makes this quick and consistent.
- Use freshly shredded cheese rather than pre-shredded bags for a smoother melt and better flavor.
- Do not overcook the squash in the skillet — it will continue cooking in the oven and can become mushy.
- Let the casserole rest before serving so it firms up and slices cleanly.
- Swap the cheddar for pepper jack cheese for a little heat, or stir in cooked bacon for a smoky version.
- Refrigerate leftovers in an airtight container for up to 4 days. Reheat individual portions in the microwave or the full dish covered at 350°F for about 15 minutes.
- Freezing is not recommended, as the texture of the squash becomes watery after thawing.
- You can assemble the casserole up to a day ahead, cover, and refrigerate before baking.
- For a gluten-free version, substitute gluten-free crackers or gluten-free panko breadcrumbs.
Private Notes
Tried this recipe?
Let us know how it was!Conclusion
This zucchini and squash casserole recipe is one of those dishes that quietly becomes a staple once you make it a couple of times.
It is warm, cheesy, and endlessly adaptable for a crowd, a weeknight dinner, or a fridge full of extra garden squash.
Give it a try this week, and let me know in the comments how yours turned out or what variation you tried.
If you make this recipe, I would love to see it. Share a photo here, and do not forget to leave a rating below.
Recommended:
- Sweet Potato Casserole Recipe
- Savory Sweet Potato Casserole Recipe
- Meatloaf and Mashed Potatoes
- Southern Fried Chicken Recipe
- Cornbread Biscuits Recipe
