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This yellow squash casserole recipe is a cheesy and delicious way to enjoy the summer squash that goes crazy every summer! It’s made with basic ingredients (only 5 of them!) and takes just a few minutes to prep. Simply roast the squash, make the homemade cheese sauce, layer, and bake the cheesy squash casserole until bubbly golden brown. So easy and such a delicious way to use summer squash!
If you like healthy squash casserole recipes like this one, but have a pile of green zucchini to use, you can make this same recipe with zucchini instead, or try a zucchini casserole. On the other hand, if you have more yellow squash to use up, learn how to cook yelllow squash in 4 basic ways. You can also replace zucchini with yellow squash in my recipes for roasted zucchini, zucchini roll ups, or keto zucchini bread. These two types of summer squash are interchangeable in almost any recipe.
Why You’ll Love This Yellow Squash Casserole Recipe
- Delicate, creamy, cheesy flavor
- Soft, tender squash
- Just 5 simple ingredients (plus salt and pepper)
- Naturally low carb and gluten-free
- Delicious way to use up summer squash
Ingredients & Substitutions
This section explains how to choose the best ingredients for yellow squash casserole, what each one does in the recipe, and substitution options. For measurements, see the recipe card below.
- Summer squash – I used yellow squash, but you can also use zucchini, or even patty pan squash. Smaller squash work better in casseroles than larger ones, because they contain less water.
- Olive Oil – For roasting the squash. I like extra virgin olive oil for this summer squash casserole, but regular olive oil or avocado oil also works. You could even use melted butter for extra flavor, since the roasting doesn’t take very long.
- Shredded Cheese – I used sharp cheddar cheese , but any kind you like will work. Try Swiss, Gruyere, parmesan cheese, or other cheeses.
- Heavy Cream – This makes a rich, thick cheese sauce. Don’t replace it with half and half or other types of milk, as the sauce will be too runny. If you really want to use milk, I’d try replacing half of the cream with milk and the other half with sour cream, but I haven’t tried this. For those who might be sensitive to dairy milk (but cheese is okay), you can swap the cream with full-fat coconut milk.
- Garlic – Use fresh or jarred minced garlic. Either will work fine for yellow squash casserole.
- Sea Salt & Black Pepper – Kosher salt is also fine instead of sea salt.
VARIATION: Add onions or herbs!
I didn’t add them because I wanted to keep the ingredients simple and the prep time as fast as possible. But, a sauteed diced onion (or even caramelized onions) or a couple tablespoons of fresh thyme or parsley would make nice additions to the summer squash casserole.
How To Make Yellow Squash Casserole
This section shows how to make summer squash casserole, with step-by-step photos and details about the technique, to help you visualize it. For full instructions, including amounts and temperatures, see the recipe card below.
- Roast the squash. Slice the yellow squash into 1/4-inch-thick slices. Place them in a large bowl and season with olive oil, sea salt, and black pepper. Roast until tender.
TIP: Make sure the squash is sufficiently roasted to let the water in the squash evaporate.
Yellow squash contains a lot of water, so if you don’t roast it for long enough, your casserole can be watery.
- Make the cheese sauce. In a saucepan, combine cheddar cheese, heavy cream, garlic, sea salt, and black pepper. Heat until melted and smooth.
- Assemble. Layer the roasted squash in a large casserole dish. Pour the sauce over the vegetables and sprinkle more cheddar cheese on top.
- Bake. Place the yellow squash casserole in the oven and bake until it starts to bubble, then broil for a few minutes until golden.
- Store: Keep leftover yellow squash casserole in the refrigerator for 3-4 days. Depending on how much you have left, you can cover the baking dish with plastic wrap or aluminum foil and store that way, or transfer to an airtight container.
- Reheat: Warm up in the oven at 350 degrees F, or in the microwave.
- Freeze: After assembling the summer squash casserole, you can freeze it before or after the baking step. Freeze it before if you’re making it ahead, or after if you’re freezing leftovers. Either way, it will keep in the freezer for up to 3 months. Thaw in the fridge overnight and stir well before reheating. You may need to stir it again after reheating, too, as the sauce texture can change.
What To Serve With Yellow Squash Casserole
Summer squash casserole recipes like this one just need a main dish! Here are some ideas:
- Chicken – I usually make simple pan seared chicken breast or air fryer chicken legs while the yellow squash casserole is in the oven. It also goes surprisingly well with coconut chicken.
- Steak – Pair the casserole with a sirloin steak or filet mignon for a hearty, comforting meal.
- Seafood – Try baked salmon or pan fried tilapia, or if it’s nice enough to cook outside, grilled shrimp.
- Pork – If you really love cheese and would enjoy it in both your main dish and side dish, make stuffed pork chops. Otherwise, you can’t go wrong with skillet pork chops.
Tools For This Recipe
- Mandoline – You can use a knife to slice the squash, but using a mandoline is faster and ensures your slices have a uniform thickness.
- Medium Saucepan – This saucepan is nonstick, which is ideal for the cheese sauce in yellow squash casserole.
- Baking Dish – Bake and serve your cheesy squash casserole right in this dish!
Yellow Squash Casserole
Yellow Squash Casserole (5 Ingredients!)
This easy yellow squash casserole recipe has layers of roasted summer squash and creamy homemade cheese sauce. Just 5 ingredients!
Recipe VideoTap on the image below to watch the video.
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Tap on the times in the instructions below to start a kitchen timer while you cook.
In a large bowl, toss the slices in the olive oil, 1/2 teaspoon sea salt, and 1/4 teaspoon black pepper.
Place the squash slices in a single layer on the lined baking sheet. Roast for 10-12 minutes, until tender.
Layer the roasted squash in a 9×13 baking dish.
In a medium saucepan, combine 2 1/4 cups cheddar cheese, heavy cream, garlic, 1/4 teaspoon sea salt, and 1/8 teaspoon pepper and heat over medium heat, until melted and smooth.
Pour the sauce over the squash and sprinkle the remaining 1/2 cup cheddar cheese on top.
Bake for 20-25 minutes until the casserole starts to bubble. Switch to broil for 2-3 minutes until the cheese is golden to your liking.
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Serving size: 1/12 of entire casserole
Nutrition facts are provided as a courtesy. Have questions about calculations or why you got a different result? Please see our nutrition policy.
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