If you grew up eating at a Southern table in summer, yellow squash casserole was probably there. Tender squash, sweet onion, sharp cheddar, and a buttery cracker crust – it's the kind of dish that disappears before anything else on the table. This southern squash casserole recipe keeps everything that makes the original worth making, with a few tips to help you avoid the one problem that ruins most versions: a watery filling.
Active Time: 20 minutes
Total Time: 50 minutes
Servings: 6–8
Ingredients
For the Filling:
- 2 lbs yellow summer squash (about 6 cups sliced)
- ½ cup sweet onion, diced (Vidalia works best)
- 2 tbsp unsalted butter
- 1 large egg, beaten
- ⅓ cup mayonnaise (Duke's preferred)
- ⅓ cup sour cream
- 1½ cups sharp cheddar cheese, freshly grated
- ½ tsp salt
- ¼ tsp freshly ground black pepper
For the Topping:
- 1 sleeve Ritz crackers, crushed (about 1 cup crumbs)
- 3 tbsp unsalted butter, melted
Instructions
Preparation
Preheat the oven to 350°F and grease an 8x8-inch or 2-quart baking dish. Slice the squash into even rounds, then dice the onion. Melt 2 tablespoons of butter in a large skillet over medium heat. Add the squash and onion, cooking for 8–10 minutes until both are soft and tender.
This next step matters more than most recipes admit: drain the cooked vegetables in a colander and press out the excess liquid with a paper towel or the back of a spoon. Skipping this step is what turns a southern squash casserole into soup.
Cooking
In a large bowl, whisk together the egg, mayonnaise, sour cream, salt, and black pepper. Fold in the grated cheddar, then add the drained squash and onion mixture. Stir until everything combines evenly.
Pour the filling into the prepared baking dish. In a small bowl, toss the crushed Ritz crackers with the melted butter until coated. Spread the cracker topping evenly over the squash mixture.
Bake uncovered at 350°F for 25–30 minutes, until the edges bubble and the topping turns golden brown.
Serving
Let the casserole rest for 5–10 minutes before serving – it sets up better and slices more cleanly. Serve alongside grilled chicken, roasted pork, or a simple green salad. Leftovers reheat well in a 325°F oven for about 15 minutes.
Nutritional Value Per One Serving
Nutrition Facts | One Serving (based on 8 servings)
- Calories: 285
- Total Fat: 22g
- Saturated Fat: 9g
- Cholesterol: 65mg
- Sodium: 390mg
- Total Carbohydrates: 14g
- Dietary Fiber: 1g
- Sugars: 4g
- Protein: 8g
Values are estimates based on standard ingredient amounts. Actual values vary by specific brands used.
Tips and Variations
Getting the best southern squash casserole comes down to a few small decisions that make a real difference.
- Drain well. Press the cooked squash firmly – excess water is the most common reason this dish turns out runny rather than creamy
- Grate your own cheese. Pre-shredded cheddar contains anti-caking agents that affect how it melts into the filling
- Don't overbake. Pull the casserole when the top is golden, not dark – overbaking dries out the filling
For variations worth trying:
- Zucchini twist: Swap half the yellow squash for zucchini. The flavor stays mild, but the color adds visual contrast
- Add heat: A pinch of cayenne or a few dashes of hot sauce in the egg mixture gives the filling a quiet kick without overpowering the cheese
- Make it ahead: Assemble everything the day before, cover tightly, and refrigerate. Add the cracker topping right before baking so it stays crisp
Conclusion
This easy southern squash casserole is the kind of recipe that earns its place on the table without asking for much. The ingredients are simple, the method is straightforward, and the result is genuinely good – creamy inside, crisp on top, and tasting like something someone's grandmother made with care. Whether you're cooking for a weeknight dinner or a summer gathering, this recipe for southern squash casserole delivers every time. Make it once and it becomes a regular.
For more delightful recipes, check out our collection of main dishes.