Go Back

Southern Squash Casserole

Southern squash casserole with a buttery Ritz cracker crust and cheesy custard-style filling. Bakes at 350°F until golden and set, with tender yellow squash folded through for a comforting side dish.
Print Recipe Pin Recipe
Prep Time 20 minutes
Cook Time 45 minutes
Total Time 1 hour 5 minutes
Servings: 8 servings
Course: Side Dish
Cuisine: Southern American
Calories: 380
Ingredients Equipment Method Notes

Ingredients
  

Yellow squash, sliced
  • 2 lb yellow squash slice into thin rounds or half-moons for even tenderness
Onion, diced
  • 1 onion dice to small pieces so they blend into the casserole
Butter
  • 2 tbsp butter used for cooking squash and onion
Shredded sharp cheddar
  • 1 cup shredded sharp cheddar sharp cheddar gives a classic Southern tang
Sour cream
  • 0.5 cup sour cream adds creaminess and helps the filling set
Mayonnaise
  • 0.25 cup mayonnaise adds richness and a tender texture
Eggs, beaten
  • 2 large eggs beaten for even custard-like binding
Salt
  • 1 tsp salt season the filling
Black pepper
  • 0.5 tsp black pepper season to taste
Ritz crackers, crushed
  • 1 sleeve Ritz crackers crushed for a buttery golden top
Melted butter
  • 3 tbsp butter melted and mixed with crumbs for the crust

Equipment

  • 1 sheet pan
  • 1 Dutch oven

Method
 

Prep and preheat
  1. Preheat the oven to 350°F and grease a 9x13-inch baking dish with a light coating. Set the dish aside for filling.
Cook squash and onion
  1. Cook the sliced yellow squash and diced onion in 2 tablespoons butter for 10-12 minutes until tender. Stir occasionally so the squash softens evenly.
  2. Drain the cooked squash and onion well in a colander. Press lightly to remove extra moisture before mixing.
Make the filling
  1. In a mixing bowl, combine the shredded sharp cheddar, sour cream, mayonnaise, beaten eggs, salt, and black pepper. Mix until smooth and evenly combined.
  2. Fold the drained squash and onion into the cheese mixture. Stir just until everything is coated.
  3. Spread the filling into the greased baking dish. Level the top so the crust bakes evenly.
Add topping and bake
  1. Toss the crushed Ritz crackers with the 3 tablespoons melted butter. Make sure the crumbs look evenly moistened.
  2. Sprinkle the buttery crushed crackers over the top of the casserole. Use an even layer for consistent browning.
  3. Bake for 30-35 minutes at 350°F until the top is golden and the center is set. Look for bubbling edges and a firm, sliceable middle.

Notes

Pro tip: draining the squash well is key—extra moisture can keep the center soft instead of set. Refrigerate leftovers in an airtight container for up to 3-4 days; reheat at 350°F until warmed through. Freezing is not recommended because the creamy filling can separate after thawing; a dairy-light swap is using reduced-fat cheddar and light sour cream for a lighter version.