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Buttery Squash and Zucchini Casserole is a show stopper! The crispy golden brown cracker crumbs add so much texture to a creamy and delicious casserole base. Perfect for a Thanksgiving table!
This Squash and Zucchini Casserole has been a top Thanksgiving dish for me for the better part of a decade.
As in, I can skip the turkey entirely if you make me a squash and zucchini casserole and give me a spoon.
In fact, before Little Spice Jar ever came into fruition, I told my old coworker about this squash casserole at work one day. I described the tender zucchini and yellow squash topped with buttery cracker crumbs, hints of garlic and red pepper flakes, and a creamy casserole base. She was intrigued.
She ended up making it that year for Thanksgiving. Years later, after we had both moved on from said job, she messaged to tell me she still makes it every Thanksgiving.
I know I sound dramatic when I say that a side dish like zucchini casserole can change your life, but I totally mean it.
Ingredients for Squash and Zucchini Casserole
- Zucchini Squash and Yellow Squash: I use ¾ pound zucchini. This is 2 medium zucchini. You’ll also use ¾ pound yellow squash. Feel free to use one or both varieties. Cut thick rounds then slice into semi circles.
- Salted Butter and Oil: we’ll use a little of each here. Butter gives it the flavor. Oil raises the temperature of the butter to keep it from browning or burning.
- White Onions: we’ll saute the onions in butter and add them to the casserole along with the other veggies.
- Butter Crackers: feel free to use Ritz crackers here if you prefer, I usually use these instead. During recipe testing, I tested both, so both work well.
- Seasonings: you’ll need kosher salt, black pepper, red pepper flakes, and garlic powder. You can add other seasonings like oregano or some dried thyme if you prefer, but for us, we like it as written.
- Cheese: I use freshly grated or shredded parmesan cheese and sharp cheddar. Sharp cheddar gives this the edgy flavor that the casserole needs, but medium cheddar does work if you prefer that instead.
- Sour Cream: while recipe testing, I did try a variation here to swap the sour cream with greek yogurt. I will say, it didn’t give it the same great taste for me, so I do suggest opting for full fat sour cream here.
Recipe Tips
- I like to slice the zucchini and the yellow squash a bit thicker for a casserole. This allows the squash to stand up to the double cooking method. Since we’re starting the zucchini in a pan and finishing in the oven, slicing the zucchini too thin would cause for it to lose its vibrance and possible burn in the oven.
- Save half the crackers for the top, and add half into the mix. I like to use the cracker crumbs to help absorb any moisture from the zucchini instead of breadcrumbs or panko. Using crackers here not only cuts down on ingredients it also gives it a cohesive taste. And personally, I love the textural variance when some of them soften slightly and the others are crunchy!
- I like to bake this in an 8×8 baking dish making it the perfect amount for a small 6 person-ish crew. You can double the recipe and bake this in an 9×13 dish to feed a larger group!
My Serving Suggestions
I would serve this squash and zucchini casserole every year on Thanksgiving along with an herb roasted turkey, and it’s already going on the menu for this year too.
It’s also great for any dinners you’re hosting during the holiday season. I would pair this with peppercorn chicken, focaccia, and a holiday salad.
You could even do a creamy mushroom pasta for a vegetarian get together. Maybe some garlic knots in the side and celery apple salad to make this fall festive.
And leftovers are great warmed up in a small ramekin in the air fryer or even just zapped in the microwave.
Other Casserole Recipes
- Creamy Green Bean Casserole
- Even Better Jiffy Corn Casserole
- Favorite Sweet Potato Souffle
- Veggie Breakfast Casserole
- Tomato Basil Breakfast Casserole
Squash and Zucchini Casserole
Ingredients
- 2 medium zucchini squash cut into ½ inch semi circles (¾ pounds)
- 2 medium yellow squash cut into ½ inch semi circles (¾ pounds)
- 6 tablespoons salted butter divided
- 2 tablespoons oil divided (such as avocado)
- 1 cup white onions finely chopped
- 2 cups butter crackers crushed up, such as Ritz
- ½ teaspoon kosher salt
- ¼ teaspoon black pepper
- ½ teaspoon garlic powder
- ¼ teaspoon red pepper flakes
- ½ cup parmesan cheese grated
- ½ cup sour cream preferably full fat
- 1 cup cheddar cheese grated (I use sharp, but medium works too)
Instructions
- PREP: Position a rack in the center of the oven and preheat the oven to 350ºF. Spray a 12×10 baking dish (or an 8×8 or 9×9 baking dish) with nonstick cooking spray.
- SEAR: Heat a large skillet over medium high heat. Add 2 teaspoon oil and a tablespoon of butter. Saute half the zucchini and yellow squash. Quickly brown the outside but don’t cook it all the way through, about 1-2 minutes. Remove to a large bowl and cook the remaining zucchini and squash the same way in 2 teaspoons of oil and another tablespoon of butter.
- SAUTE: Add 1 tablespoon of butter and another 2 teaspoons of oil to the same pan once the zucchini and squash are cooked. Once melted saute the onions for 4-6 minutes or until they soften. Season with a pinch of salt so that they soften but do’t brown. Remove the onions to the same bowl as the zucchini.
- GOLDEN: Add the remaining 3 tablespoon of butter to same pan. Once melted stir the butter crackers around until they absorb most of the butter. Remove from heat and let cool.
- COMBINE: Add the kosher salt, black pepper, garlic powder, red, pepper flakes, grated parmesan cheese, sour cream, 1 cup of butter crackers, and the cheddar cheese to the zucchini and onion mixture and stir to combine.
- DUMP: Pour mixture into the prepared baking dish and top with the remaining butter crackers.
- BAKE: no need to cover with foil, simply bake in the oven for 20-25 minutes or until the crackers are golden brown on top and the zucchini is tender to your liking. Enjoy!
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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Yesss this was AWESOME!!! Will make it again because I love these 2 veggies!!!
Oh yeah, I’d be all over this! I adore zucchini/squash casseroles. YUM!