Squash Casserole Recipe

Squash Casserole is a classic American side dish where tender yellow squash bakes in a creamy, cheesy base under a buttery, golden topping. Sliced squash and onion cook in butter first to soften and release moisture, then get folded into an egg-and-cheese mixture that turns rich and custardy in the oven. A layer of crumbs mixed with melted butter goes on top so it bakes up crisp and deeply flavored. The result is a comforting, crowd-pleasing casserole with soft squash, gooey cheese, and a crunchy top that fits right in at potlucks, Sunday dinners, and holiday tables.

Squash Casserole Recipe

Cheesy Yellow Squash Casserole is an American-style side dish where sliced yellow squash and onions bake in a creamy, cheesy base with a buttery crumb topping until the center is set and the top is golden and crisp.

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Prep Time 25 minutes mins

Cook Time 35 minutes mins

Total Time 1 hour hr

Servings: 8

Course: Side Dish

Cuisine: American

Calories: 230

Ingredients Equipment Method Notes

Ingredients

  

For the Squash Base

• 2 lb yellow squash sliced into ¼-inch rounds
• 1 small onion finely chopped
• 3 tbsp unsalted butter
• 1 tsp kosher salt
• ½ tsp black pepper

For the Cheesy Mixture

• 2 large eggs
• 1 cup shredded cheddar cheese
• ½ cup sour cream
• ¼ cup milk

For the Buttery Topping

• ¾ cup breadcrumbs or crushed buttery crackers
• 3 tbsp unsalted butter melted

Equipment

• Large cutting board
• Chef’s knife
• Large skillet
• Wooden spoon
• Large mixing bowl
• Measuring cups
• Measuring spoons
• 9×13-inch baking dish
• Small bowl
• Whisk
• Oven mitts

Method

 

Prep and sauté the squash

1. Place the yellow squash on a large cutting board, trim off the ends with a chef’s knife, then slice the squash into ¼-inch rounds.
2. Chop the onion on the cutting board with the chef’s knife into small pieces.
3. Set a large skillet on the stove over medium heat, add 3 tbsp butter, and stir with a wooden spoon until the butter melts.
4. Add the sliced squash and chopped onion to the skillet, sprinkle 1 tsp salt and ½ tsp pepper over the top with measuring spoons, and cook for 10 minutes, stirring often with the wooden spoon until the squash softens and some of the liquid cooks off.
5. Turn off the heat and let the squash mixture cool slightly in the skillet.

Mix the cheesy base

1. Crack 2 eggs into a large mixing bowl and beat them with a whisk until smooth.
2. Add 1 cup shredded cheddar, ½ cup sour cream, and ¼ cup milk to the bowl and whisk until the mixture looks creamy and combined.
3. Spoon the warm squash and onion mixture from the skillet into the mixing bowl and stir with the wooden spoon until all the slices are coated in the cheesy mixture.

Make the buttery topping

1. Put ¾ cup breadcrumbs or crushed crackers into a small bowl and pour 3 tbsp melted butter over them with a measuring spoon.
2. Stir the crumbs and butter together with a spoon until the crumbs look evenly moistened.

Assemble and bake

1. Lightly grease a 9×13 inch baking dish, then pour the squash mixture into the dish and spread it into an even layer with the wooden spoon.
2. Sprinkle the buttery crumb mixture evenly over the top of the squash in the baking dish.
3. Place the baking dish on the middle rack of a preheated 350°F oven using oven mitts and bake for 35 minutes until the casserole is bubbling around the edges and the topping is golden brown.

Serve

1. Remove the baking dish from the oven with oven mitts and let the casserole sit for 5 minutes so it sets slightly, then scoop portions out with a large spoon and serve warm as a side dish.

Notes

• Slice the squash evenly on the cutting board so it cooks at the same speed and bakes evenly in the casserole.
• Sautéing the squash first in the skillet helps cook off extra liquid, which keeps the baked casserole from turning watery.
• Leftovers reheat well in the oven at 350°F until hot, and the topping stays more crisp than it would in the microwave.