Zucchini Squash and Corn Casserole
Every summer, it happens. The garden goes from a few hopeful sprouts to an absolute jungle of zucchini and squash. You give it to neighbors, you try to sneak it into every meal, and still, they keep coming.
I found myself in that exact spot, staring at a counter full of green and yellow squash, feeling a little overwhelmed. I needed a recipe that wasn’t just another side dish, but something truly delicious that my family would actually ask for.
That’s how this Zucchini Squash and Corn Casserole was born. It’s creamy, cheesy, and packed with the sweet pop of corn. It transforms humble summer squash into the star of the dinner table.
This isn’t your average mushy vegetable bake. This is the recipe that will make you look forward to that garden abundance. Let’s make something amazing together.
What You’ll Need
Here are the simple ingredients that come together to create this incredible casserole. Fresh is fantastic, but I’ve got notes on using frozen stuff too.
- 4 cups shredded zucchini (about 2 medium)
- 2 cups shredded yellow squash (about 1 large)
- 1 cup sweet corn (fresh or frozen)
- 1 small onion, finely chopped
- 1 cup shredded sharp cheddar cheese, divided
- 1/2 cup grated Parmesan cheese
- 1 cup sour cream or plain Greek yogurt
- 2 large eggs, lightly beaten
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1 teaspoon garlic powder
- 1/2 cup panko breadcrumbs
- 2 tablespoons unsalted butter, melted
How to Make Zucchini Squash and Corn Casserole
Follow these simple steps for a perfect casserole every time. The most important part is getting the moisture out of the squash!
Step 1: Preheat your oven to 375°F (190°C). Grease a 9×13 inch baking dish with butter or a little cooking spray.
Step 2: Place the shredded zucchini and yellow squash in a colander set over the sink. Sprinkle them with the 1 teaspoon of salt and let them sit for about 15-20 minutes. The salt will draw out excess water.
Step 3: After waiting, use your hands to squeeze as much liquid as you possibly can from the shredded squash. You can also press it against the colander with a spoon. This step is critical to avoid a watery casserole.
Step 4: In a large mixing bowl, combine the squeezed squash, sweet corn, chopped onion, 1/2 cup of the cheddar cheese, the Parmesan cheese, sour cream, and beaten eggs.
Step 5: Season the mixture with the black pepper and garlic powder. Stir everything together until it’s well combined.
Step 6: Pour the mixture into your prepared baking dish and spread it out into an even layer.
Step 7: In a small bowl, mix the panko breadcrumbs with the melted butter. Sprinkle this mixture evenly over the top of the casserole. Then, top it all off with the remaining 1/2 cup of cheddar cheese.
Step 8: Bake for 30-35 minutes, or until the casserole is bubbly and the top is golden brown and crispy.
Step 9: Let the casserole rest for at least 10 minutes before cutting and serving. This helps it set up, so you get nice clean slices.
Pro Tips From My Kitchen
After making this dish dozens of times, I’ve learned a few things that take it from good to great.
- The Squeeze is Everything: I can’t say this enough. If you think you’ve squeezed enough water out of the zucchini, squeeze it again. A handful at a time works best. A dry squash mix means a creamy, not soupy, final dish.
- Fresh Corn is a Game Changer: If it’s in season, use fresh corn sliced right off the cob. It has a sweet, crisp pop that you just can’t fully replicate with frozen. If using frozen, make sure to thaw it and pat it dry first.
- Shred Your Own Cheese: Pre-shredded cheese is coated in starches to prevent clumping, which can make your casserole a bit greasy. Taking two minutes to grate a block of sharp cheddar results in a much smoother, meltier texture.
- Don’t Skip the Rest: Letting the casserole sit for 10 minutes before you dive in is so important. It allows the egg and cheese to set, so it holds its shape beautifully when you serve it.
Tools For the Job
You don’t need any fancy equipment for this recipe, just a few kitchen basics.
- 9×13 inch Baking Dish
- Box Grater or Food Processor with shredding attachment
- Large Mixing Bowl
- Colander
- Spatula or Large Spoon
- Knife and Cutting Board
Substitutions and Variations
This recipe is very flexible. Feel free to swap things out based on what you have or what you like.
| Ingredient | Substitution | Notes |
|---|---|---|
| Sour Cream | Plain Greek Yogurt | Adds a similar tang and creaminess. |
| Panko Breadcrumbs | Crushed Ritz crackers | Gives a buttery, rich topping. |
| Sharp Cheddar | Monterey Jack or a Colby blend | Changes the flavor but still melts well. |
| Onion | Leeks or shallots | Leeks provide a milder, sweeter flavor. |
Want to add a little something extra? Try these variations:
- Make it Spicy: Add a finely diced jalapeño or a pinch of red pepper flakes to the mixture.
- Add Some Protein: Mix in 1 cup of cooked, crumbled bacon or sausage for a heartier dish.
- Herb Garden Delight: Stir in 2 tablespoons of fresh chopped parsley or chives for a burst of fresh flavor.
Dietary Swaps & Nutrition
Need to adjust this for a specific diet? No problem. Here are some easy swaps.
- Gluten-Free: Use your favorite gluten-free panko or breadcrumbs for the topping. The rest of the casserole is naturally gluten-free.
- Lower Carb / Keto-Friendly: The corn is the main source of carbs here. You can omit it or replace it with finely chopped bell peppers. For the topping, use crushed pork rinds or almond flour mixed with the butter.
- Dairy-Free: Use a dairy-free sour cream alternative and your favorite brand of dairy-free shredded cheddar.
Here’s an approximate nutritional breakdown. This can vary based on your specific ingredients.
| Nutrition (per serving, 8 servings total) | Approximate Amount |
|---|---|
| Calories | 250 kcal |
| Carbohydrates | 15g |
| Protein | 12g |
| Fat | 16g |
Meal Pairing & Make-Ahead Tips
This casserole is fantastic on its own, but it also plays well with others.
It’s the perfect companion for simple main courses like grilled chicken breasts, baked salmon, or a juicy pork chop. It basically turns any simple protein into a full, satisfying meal.
To make this dish ahead of time, you can assemble the entire casserole without the topping. Cover it tightly with plastic wrap and store it in the refrigerator for up to 24 hours. When you’re ready to bake, just add the breadcrumb and butter topping and bake as directed, adding 5-10 minutes to the cook time.
Leftovers and Storage
If you’re lucky enough to have leftovers, they store beautifully.
Allow the casserole to cool completely, then cover the dish tightly or transfer leftovers to an airtight container. It will keep in the refrigerator for up to 4 days.
For reheating, the oven or a toaster oven is your best bet. A few minutes at 350°F will bring back that crispy topping and heat it through without making it soggy like a microwave can.
Frequently Asked Questions
Q1. My casserole came out watery. What did I do wrong?
Ans: This is the most common issue, and it almost always comes down to not squeezing enough water from the squash. The salting step helps, but you really need to use your hands or a cheesecloth to wring out that excess moisture before mixing.
Q2. Can I use only zucchini or only yellow squash?
Ans: Absolutely. If you only have one type of squash, just use a total of 6 cups of it. The flavor and texture will be very similar and just as delicious.
Q3. Can I freeze this casserole?
Ans: You can, but the texture will change a bit upon thawing. The squash can become softer. I recommend freezing it unbaked and without the topping. Thaw it in the fridge overnight, pour off any extra liquid, add the fresh topping, and then bake.
Q4. What is panko and can I use regular breadcrumbs?
Ans: Panko is a type of Japanese breadcrumb that is flakier and lighter than traditional breadcrumbs, so it creates an extra-crispy topping. You can definitely use regular breadcrumbs if that’s what you have on hand!
Wrapping Up
There you have it—a simple, crowd-pleasing casserole that turns summer squash into something truly special. It’s proof that with a little cheese and a crispy topping, you can make any vegetable irresistible.
I really hope you give this recipe a try. It’s become a staple in my home, and I think it will in yours, too.
If you make it, I’d love to hear how it turned out! Leave a comment below with your experience or any questions you might have.
