Yellow Squash Casserole – Creamy, cheesy, and downright gorgeous, this casserole is magnificent as a stand-alone dish or as a comforting side. Vibrant yellow squash in a rich, cheesy sauce is exceptionally delicious. Covered with a buttery, crunchy topping, it’s far from your ordinary casserole!
My neighbor came to my door the other day with her arms full of squash. Her garden produced a bumper crop this year, and she wanted to share the wealth! I was ecstatic to get some garden-fresh veggies. My son… not so much. He isn’t the world’s greatest squash lover. I knew I’d have to get creative if I wanted to have my squash and eat it, too!
Although squash may appear bland at first glance, it’s the perfect blank canvas for big flavors. In this yellow squash casserole, the squash, mayonnaise, and cheeses meld together in mysterious ways, making this humble vegetable marvelous! It’s a great way to get even non-squash lovers (including my son!) craving their vegetables!
What’s Special About It?
What’s Special About Yellow Squash?
Yellow squash is abundant in the summer months, making it a popular variety of summer squash. It has gorgeous golden skin, creamy white flesh, and large-ish seeds. Although it looks like yellow zucchini, yellow squash has a rounder base and a slightly sweet, nutty flavor. Add that to a cheesy casserole, and you’ll be in yellow squash heaven.
- Seasonings – Onion, garlic, and thyme create this dish’s earthy and aromatic flavor base. Depending on your preference, you could also use parsley, oregano, or basil.
- Yellow Squash – The star player is nutritious and has a gorgeous golden color.
- Eggs – The added protein also holds everything together. Yum!
- Sour Cream & Mayo – Makes the dish rich, creamy, and zingy for the win.
- Cheese – Cheddar cheese is my fave in this dish because of its sharp, tangy flavor. Monterey Jack, Gruyere, or another good melting cheese also works great.
- Topping – Crackers and butter add a delicious and crunchy texture to please even the pickiest eater.
How to Make Yellow Squash Casserole
- Prep – Lightly grease a square baking or round casserole dish (8 or 9 inches) and set aside. Slice the yellow squash and set aside.
- Cook Squash – Melt your butter in a large skillet over medium-high heat. Add onions, garlic, and thyme. Sauté for about a minute until the onions are soft and translucent. Then add the squash, season with salt and pepper, and cook, stirring frequently, until the vegetables start to soften and liquid is released, about 8-10 minutes. Remove from heat and drain any extra liquid.
- Combine – In a medium mixing bowl, stir eggs, sour cream, and mayonnaise until thoroughly combined. Then stir the egg mixture into the squash mixture, add the cheese, and mix to coat the squash. Transfer the squash casserole mixture to the prepared baking pan.
- Make Topping – In another small bowl, toss crushed crackers and butter until the butter coats the cracker crumbs. Sprinkle buttered crackers over the top of the squash.
- Cook – Bake at 350℉/177℃ for 20-25 minutes, uncovered, until the casserole is set and the topping is lightly browned. Serve hot.
- You can replace the butter crackers with cornflakes, breadcrumbs, or crumbled croutons, depending on what’s in your pantry. Or give the yellow squash casserole extra crunch by crushing potato chips on top (you won’t need the butter as a binder if you opt for chips!).
- Pump it up with more veggies! Add a sauteed bell pepper or kernels of sweet corn for extra nutrition and color!
- You can make this casserole recipe even heartier by dicing some bacon or ham and sautéing them with onion and garlic.
- Not crazy about yellow squash? You can make a butternut squash casserole by peeling, slicing, and sauteing butternut squash. You probably won’t have extra liquid to drain off, but you can proceed with the same recipe for an excellent squash casserole.
Tips and Tricks
- To prevent a mushy casserole, don’t overcook the squash. Remove it from the heat when it starts to soften, but before it gets overcooked.
- If you think the cooked squash has excess water, you can gently strain it to discard the water and allow it to cool for 5-10 minutes before adding it to the casserole.
- To maintain the beautiful texture of the squash, fold it into the casserole gently so it won’t break apart.
This squash casserole recipe is great for busy weeknight meals! You can make this deliciousness 24 hours in advance, cover it tightly with plastic wrap or foil, and refrigerate it. Then let it warm to room temperature before baking it.
Serving and Storage Instructions
This delicious yellow squash casserole is best hot out of the oven. I also like to take advantage of already having the oven on by baking chicken or a roast at the same time.
Leftovers stored in an airtight container last for 4-6 days. If it gets a little watery, just add more buttery cracker topping.😉
This incredible casserole is the perfect candidate for making ahead and freezing (it should last three months). Let it cool completely after it comes out of the oven, wrap it with plastic or foil, and freeze. Thaw it overnight in the refrigerator and heat it in the oven for a fast and satisfying side or vegetarian main dish.
Of course! Zucchini is a good substitute for yellow squash in this dish, although it may not be as sweet. Even better, you can mix the two for a variety of colors and flavors.
Eggs are there mainly to help bind all the ingredients together. However, they also add protein and make the sauce rich and creamy. 😊
Nope, no peeling is required! Everything about the yellow squash is edible, from its skin to its flesh to its seeds. How great is that? Just clean it under cool running water before preparing it.
What to Serve With Yellow Squash Casserole
This squash casserole is a solid vegetarian dish on its own. But if you have meat lovers at the table, it can be served with basically any protein. Here are some that my family loves:
- Oven-Baked Pork Chops
- Jamaican Fried Chicken
- Brown Sugar Glazed Ham
- Roasted Turkey Thighs
- Pork Tenderloin Roast
More Hearty Casserole Recipes to Try
- Grits Casserole
- Sweet Potato Casserole
- Fiesta Chicken Casserole
- Cabbage Roll Casserole
- Cheesy Hashbrown Casserole
Loaded with tender vegetables and alive with color, this yellow squash casserole is anything but boring! Did you or a neighbor have a bumper crop of vegetables this year? Sign up for my newsletter to get more creative casserole ideas!
Watch How to Make It
This blog post was originally published in May 2019 and has been updated with additional tips, new photos, and a video.
- 3 tablespoons (42g) unsalted butter
- 1 medium onion, chopped
- 2 teaspoons (10g) garlic, minced
- 2 teaspoons (1.6g) fresh thyme, chopped
- 3 pounds (1.3k) yellow squash (or zucchini)
- Salt and pepper to taste
- 2 large eggs, lightly beaten
- 4 ounces (113g) sour cream
- 4 ounces (113g) mayonnaise
- 8 ounces (113g) sharp cheddar cheese, shredded
- 2 sleeves round buttery crackers, crushed (I used Ritz)
- 1-2 tablespoons (14-28g) butter
- Preheat oven to 350℉/177℃. Lightly grease an 8- or 9-inch square baking pan or casserole dish and set aside.
- Melt butter in a large skillet over medium-high heat. Add the onions, garlic, and thyme. Sauté for about a minute until the onions are soft and translucent.
- Then add squash, season with salt and pepper, and cook, stirring frequently, until the vegetable softens and liquid is released, about 8-10 minutes. Remove from heat and drain out any extra liquid.
- In a medium mixing bowl, stir together eggs, sour cream, and mayonnaise until fully combined. Stir the egg mixture into the squash mixture, add the cheese, and mix to coat the squash.
- Transfer the squash mixture to the prepared baking pan.
- In another small bowl, toss together crushed crackers and butter. Sprinkle buttered cracker crumbs over the top of the squash.
- Bake at 350℉/177℃ for 20-25 minutes (uncovered) until the casserole is set and the topping is lightly browned. Serve hot.
Tips & Notes:
- You can replace yellow squash with zucchini or use a combination of both, but it may not be as sweet as yellow squash.
- No need to peel yellow squash. You can eat its entirety – skin, seeds, flesh, and even its flowers.
- Never brush them to clean as you would potatoes because the skin is too tender. Just clean it in cool running water before using it. Rub any dirt spots on its skin using your thumb or with a damp cloth.
- Remove as much liquid as possible when cooking yellow squash to prevent a watery casserole.
- Don’t overcook the squash to avoid a mushy casserole.
- You may replace Ritz with any crackers you have; cornflakes, potato chips, panko breadcrumbs, or crumbled croutons all work great.
- Please keep in mind that nutritional information is a rough estimate and can vary greatly based on the products used.