Classic Southern Squash Casserole
This classic Southern squash casserole combines tender yellow summer squash with a creamy, cheesy filling and a golden, buttery cracker topping. Sautéing the squash instead of boiling removes excess moisture, ensuring a rich, scoopable texture every time.
Equipment
- 9x9-inch Baking Dish - or similar 2-quart dish
- Large skillet
- Fine Mesh Colander - or strainer
- Large mixing bowl
- Medium mixing bowl
- Whisk
- Wooden spoon - or silicone spatula
- Box grater - for freshly shredding cheese
- Zip-top bag - for crushing crackers
- Rolling Pin - or heavy cup for crushing crackers
- Measuring cups
- Measuring spoons
- Paper towels - for pressing moisture from cooked squash
Ingredients
- 2 lbs yellow summer squash - 900g, sliced into ¼-inch (6mm) rounds
- ½ cup yellow onion - 75g, finely diced
- 2 cloves garlic - minced
- 4 tablespoons salted butter - 56g, divided
- 1 cup full-fat sour cream - 240g
- 2 tablespoons mayonnaise - 30g
- 2 large eggs - lightly beaten
- 1½ cups sharp cheddar cheese - 170g, freshly shredded and divided
- ½ teaspoon salt
- ¼ teaspoon black pepper
- ¼ teaspoon cayenne pepper - optional, for a subtle kick
- 1 sleeve Ritz crackers - about 36 crackers or 140g, coarsely crushed
- cooking spray - for greasing the dish
Instructions
- Preheat oven to 350°F (175°C). Lightly grease a 9x9-inch baking dish with cooking spray.
- Wash squash and slice into ¼-inch rounds. Finely dice onion and mince garlic.
- Melt 2 tablespoons butter in a large skillet over medium heat. Cook onion for 3 minutes until soft, add garlic for 30 seconds.
- Add squash, salt, pepper, and cayenne. Cook for 8-10 minutes, stirring often, until tender and most liquid has evaporated.
- Transfer squash to a colander and drain for 5 minutes. Press gently with paper towels to remove excess moisture.
- In a large bowl, whisk sour cream, mayonnaise, and eggs until smooth. Stir in 1 cup of shredded cheddar.
- Fold the drained squash into the creamy mixture until evenly coated. Transfer to the prepared baking dish.
- Sprinkle remaining ½ cup of shredded cheddar over the filling.
- Melt remaining 2 tablespoons butter. Crush crackers in a zip-top bag, then toss with melted butter until coated.
- Spread buttered cracker crumbs evenly over the casserole.
- Bake uncovered for 30-35 minutes until topping is golden and filling is bubbling. Let rest for 5 minutes before serving.
Notes
- Moisture is key: Sautéing rather than boiling the squash removes excess water. Be sure to drain and press the squash well before mixing into the filling to prevent a watery casserole.
- Shred your own cheese: Pre-shredded cheese contains anti-caking agents that prevent smooth melting. Freshly shredded cheddar gives you a creamier, more cohesive filling.
- Make it ahead: Assemble the casserole through adding the cheese layer, cover, and refrigerate overnight. Add the cracker topping just before baking, and add 5-10 minutes to the bake time.
- Freezing instructions: Freeze unbaked casserole (without topping) for up to 3 months. Wrap tightly in plastic wrap and foil. Add fresh cracker topping just before baking.
- Cracker texture: Don't over-crush the crackers. Leave some coarse crumbs and small chunks for the best crispy, textured topping.
- Variation - add zucchini: Use a 50/50 blend of yellow squash and zucchini for a more colorful dish. Zucchini releases more moisture, so drain extra well.
- Spice it up: Increase cayenne to ½ teaspoon or add 1 teaspoon of smoked paprika for a bolder flavor profile.
- Cheese swaps: Try Gruyère, Monterey Jack, or Pepper Jack in place of cheddar for a different flavor twist.
- Add protein: Stir in 1 cup of shredded rotisserie chicken or cooked crumbled bacon to turn this into a more complete one-dish meal.
- Leftovers: Store in the refrigerator for up to 4 days. Reheat in a 325°F oven for 15-20 minutes, covered with foil to prevent over-browning.