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A golden-brown squash casserole with a crispy topping in a white baking dish.

Classic Creamy Squash Casserole

This classic creamy squash casserole features tender yellow squash and onions baked in a rich, cheesy sauce, topped with a buttery, crispy cracker crust. It's a comforting side dish perfect for any meal.
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Prep Time 20 minutes
Cook Time 35 minutes
Total Time 55 minutes
Servings 8 servings

Equipment

  • Large skillet or pot
  • Large bowl
  • 9x13 inch baking dish
  • Small bowl

Ingredients
  

Casserole

  • 2-3 pounds yellow squash (summer squash recommended), sliced or diced
  • 1 medium medium onion chopped
  • 1/4 cup butter (1/2 stick), divided
  • 1 cup sour cream (or mayonnaise, or a combination)
  • 1-2 cups shredded cheddar cheese (sharp or mild, to preference)
  • 1 large egg lightly beaten
  • 1 teaspoon salt (or to taste)
  • 1/2 teaspoon black pepper (or to taste)
  • 1/2 teaspoon garlic powder
  • 1/4 teaspoon paprika

For topping

  • 1 sleeve crushed Ritz crackers (about 1.5 cups) (or Panko breadcrumbs or cornflakes)
  • 2 tablespoons melted butter (for topping)

Instructions
 

Prep the Squash

  • Slice or dice the yellow squash. Melt half the butter in a large skillet, then add chopped onion and cook until softened for about 5 minutes.
  • Add the squash to the skillet and cook, stirring occasionally, until tender-crisp and most liquid has evaporated (10-15 minutes). Drain any remaining liquid thoroughly.

Make the Filling

  • In a large bowl, combine the cooked squash and onion. Add sour cream, shredded cheese, beaten egg, remaining melted butter, salt, pepper, garlic powder, and paprika. Mix gently until well combined.

Prepare for Baking

  • Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.

Assemble the Casserole

  • Pour the squash mixture evenly into the prepared baking dish.

Add the Topping

  • In a small bowl, combine crushed crackers with 2 tablespoons of melted butter. Sprinkle this mixture evenly over the squash filling.

Bake

  • Bake for 25-35 minutes, or until the casserole is bubbly around the edges and the topping is golden brown and crisp.

Rest and Serve

  • Remove from the oven and let rest for 5-10 minutes before serving. This allows the casserole to set slightly, making it easier to serve.

Notes

For extra flavor, you can add a pinch of cayenne pepper to the squash mixture. To make this dish vegetarian, ensure you use a vegetarian-friendly cheddar cheese. Leftovers can be stored in the refrigerator for up to 3 days and reheated. This casserole is also great for meal prepping and can be assembled ahead of time and baked later.