This Southern Cheesy Squash Casserole Recipe with Sour Cream is rich, cheesy, and topped with a buttery ritz cracker crumb that turns golden brown in the oven. It’s the ultimate comforting side dish for summer months and beyond—perfect with fried chicken or all on its own.
Why You’ll Love It
There’s just something about a cheesy squash casserole that makes me so happy.
Maybe because it's been a staple at our family gatherings for years.
Or maybe because it's loaded with layers of tender squash, sweet onion, sharp cheddar cheese, and a creamy base made with sour cream and cream cheese.
Or because this one skips the canned soup and egg mixture and goes all in on fresh flavor, making it the best squash casserole I’ve ever made!
The squash mixture gets cooked down with aromatic sage and lightly caramelized onions in a large skillet before being folded into a creamy sauce that’s downright dreamy.
Then it’s topped with a buttery cracker crumb made from crushed Ritz crackers (or really any butter flavored crackers you’ve got on hand) and a few dabs of melted butter that make the top of the casserole extra golden and crunchy.
It’s one of my go-to recipes for thanksgiving while also being a great recipe for using up summer squash from your garden or a farmers market haul. Plus, it travels well—making it perfect for family dinners, potlucks, or weekend get-togethers. Oh and bonus: it’s naturally vegetarian, so it can double as a cozy main for any veggie-lovers at the table!
Whether you’re deep in the cooler months and craving something cozy, or you’re looking for a delicious side dish to pair with grilled pork chops or BBQ, this squash casserole is a classic dish you’ll want to make again and again.
Ingredients & Substitutions
Here are the simple ingredients you'll need to make this perfect side dish. And if you're looking for exact measurements for htis cheesy squash casserole, be sure to check the recipe card at the bottom of this post.
- Sweet Onion: Vidalia onions are a must down here in the south. They add sweetness and depth. But if you can't find them - no worries! You can use yellow or white onions if needed.
- Yellow Squash: Look for small yellow squash or zucchini squash for the best texture. Zucchini casserole fans, this recipe is for you too! Feel free to use what you've got!
- Fresh Sage: Brings herby warmth, but you can sub with thyme or your favorite all purpose seasoning if sage isn't right for the occasion.
- Sour Cream: The creamy base of the sauce. You could sub with plain Greek yogurt (full fat) or a can of cream of mushroom soup in a pinch.
- Mayonnaise: If you are not a fan of mayo, don't worry - you can't taste it!! But it does make this yellow squash casserole extra decadent!
- Cream Cheese: Make sure it’s at room temperature so it melts smoothly. If you don't have cream cheese, you can leave it out.
- Sharp Cheddar: The sharper the better! Adds richness and a tangy bite. But feel free to swap out for another type of cheese like white cheddar, asiago, or pepper jack.
- Parmesan Cheese: For that salty, nutty layer of flavor. Another hard, aged italian cheese also works.
- Butter Crackers: Ritz crackers or any buttery crackers work here for teh topping on this easy casserole recipe. You could also use stuffing mix or bread crumbs for a different texture.
- Salted Butter: Divided between the skillet and the buttery ritz cracker topping. Unsalted butter works too—just add a pinch of salt to make up for it.
- Kosher Salt & Black Pepper: Always to taste. A pinch of cayenne pepper would be a great way to add heat.
How to Make It
Here are the detailed step-by-step instructions on how my family has been making this cheesy squash casserole since I was a kid!
- PREHEAT OVEN: Preheat your oven to 400°F.
- SAUTÉ ONIONS: Add 2 tablespoons of salted butter to a large skillet over medium heat. Once melted, stir in the finely chopped sweet onion and a pinch of kosher salt. Cook for 5-10 minutes until the onions are soft and lightly golden.
- ADD SQUASH: Toss in the sliced yellow squash and another pinch of salt. Cook for 5 minutes, just until the squash starts to brown and soften slightly. If your squash are excess water, push them to the side of the pan, tilt it, and carefully use a wad of paper towels to remove the excess liquid.
- STIR IN HERBS & SAUCE: Add in the sage and stir in the sour cream and mayo. Let it melt into the squash mixture before adding the room temperature cream cheese, sharp cheddar, and parmesan cheese. Stir until everything is melted and bubbling into a creamy cheese sauce.
- TRANSFER TO BAKING DISH: Spoon the squash casserole mixture into a greased casserole dish or baking dish prepped with cooking spray.
- ADD TOPPING: Sprinkle the top of the casserole with the delicious topping of crushed buttery cracker crumbs, then dot with the remaining tablespoon of melted butter - evenly across the surface
- BAKE & SERVE: Bake uncovered for 8-10 minutes or until the top is golden brown and bubbling. Remove from the oven and let rest for 10 minutes before serving.
- SAVE: If you have any leftover squash casserole (which is doubtful!) store them in airtight container or cover the baking dish with plastic wrap and refrigerate. It reheats beautifully and might even be better the next day.
What goes with Squash Casserole?
Here are a few of my favorite side dishes to serve with this easy squash casserole recipe.
- My Mom's Southern Pineapple Cheese Casserole Recipe
- Easy Cheesy Broccoli Casserole Recipe with Ritz Crust
- Microwave Sweet Potatoes
- Green Bean Casserole Appetizer Bites
- Brown Sugar Roasted Butternut Squash
- Spaghetti Squash Pizza Casserole Bowls with Pepperoni & Fresh Basil
Or be sure to check out my Southern Thanksgiving Recipe Collection!
Recipe
Southern Cheesy Squash Casserole Recipe with Sour Cream
Ingredients
- 3 tablespoon Salted Butter divided
- 2 medium Sweet Onions finely diced
- 3 lbs Yellow Squash cut into thick coins
- 2 tablespoon Fresh Sage julienned (or 1 teaspoon all purpose seasoning)
- 1 cup Sour Cream
- ¼ cup Mayonnaise
- 4 oz Cream Cheese room temperature
- 8 oz Sharp Cheddar Cheese shredded
- ⅓ cup Parmesan Cheese grated
- 1.5 cups Butter Crackers crushed
- Kosher Salt to taste
Instructions
- Preheat oven to 400°F.
- Add 2 tablespoons of salted butter to a large skillet over medium heat.
- Once melted, add chopped sweet onions and a pinch of salt. Cook for 5–10 minutes until softened and lightly browned.
- Add squash and another pinch of salt. Cook for 5 minutes until squash begins to soften.
- Stir in fresh sage (or all purpose seasoning), sour cream and mayonnaise. Mix until combined.
- Add room temperature cream cheese, shredded cheddar, and grated parmesan. Stir until everything is melted and bubbling.
- Transfer squash mixture to a greased casserole dish.
- Top with crushed crackers and dot with the remaining tablespoon of butter.
- Bake for 8–10 minutes until golden brown and bubbly.
- Remove from oven and let rest for 10 minutes before serving.
Video
Notes
