Yellow Squash Casserole

Summer squash casserole with browned cheese and breadcrumb topping

The Spruce Eats / Diana Rattray

Prep: 15 mins
Cook: 60 mins
Total: 75 mins
Servings: 4 servings
Nutrition Facts (per serving)
545 Calories
42g Fat
31g Carbs
12g Protein
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Nutrition Facts
Servings: 4
Amount per serving
Calories 545
% Daily Value*
Total Fat 42g 54%
Saturated Fat 15g 77%
Cholesterol 110mg 37%
Sodium 701mg 30%
Total Carbohydrate 31g 11%
Dietary Fiber 4g 14%
Total Sugars 8g
Protein 12g
Vitamin C 10mg 51%
Calcium 265mg 20%
Iron 2mg 13%
Potassium 457mg 10%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

This yellow summer casserole is a favorite all year round, great for family meals during the summer but also popular for holiday dinners, especially in the South. You can use yellow straight neck or crookneck squash or make the casserole with zucchini or another type of summer squash. It's a great way to use any kind of summer squash when you are enjoying nature's bounty from your garden (or your neighbor's garden).

Zucchini and summer squash are abundant during the summer months because they are easy to grow and mature relatively quickly. If you are growing it in your garden, you'll need plenty of recipes to use it. If one of your solutions is to share your squash with friends, family, and co-workers, include a link to this recipe.

The recipe is easily scaled up for a potluck dish or large family dinner. This squash casserole is a good side dish that can take the place of a heavier starch, and it goes well with just about any protein, especially chicken, fish, or pork chops. Another vegetable like green beans or a fresh green salad will complement the meal.

"This summer squash casserole is a great way to get non-veggie eaters to love their vegetables! It's really quick to whip up and reminded me of a mac and cheese side dish. This would be perfect with a steak and a green vegetable for a summer dinner." —Tracy Wilk

Summer Squash Casserole
A Note From Our Recipe Tester


  • 2 medium yellow summer squash

  • 1 teaspoon kosher salt, plus more to taste

  • 1 small onion

  • Freshly ground black pepper, to taste

  • 1 large egg

  • 1 teaspoon sugar

  • 3/4 cup shredded Cheddar cheese, divided

  • 1/2 cup mayonnaise

  • 4 tablespoons melted butter, divided, plus more for the casserole dish

  • 1 cup finely ground fresh breadcrumbs

Steps to Make It

  1. Gather the ingredients. Preheat the oven to 350 F.

  2. Slice the summer squash and place it in a medium saucepan (no need to peel or remove the seeds). Cover the squash with water and add 1 teaspoon of salt. Place the pan over high heat and bring the squash to a boil. Reduce the heat to medium-low and cover the pan; continue to cook until tender, about 10 to 15 minutes.

  3. Meanwhile, peel and finely dice the onion.

  4. Drain the squash thoroughly; return it to the saucepan, and mash it. Taste the squash and add salt and pepper, as desired.

  5. In a bowl, whisk the egg and sugar lightly. Add the mayonnaise, chopped onion, 1/2 cup of the cheddar cheese, and 2 tablespoons of the melted butter. Stir to blend thoroughly.

  6. Stir the mashed squash into the egg and mayonnaise mixture.

  7. Butter a 1-quart casserole or baking dish. Spoon the mixture into the prepared casserole.

  8. Top the casserole with the remaining 1/4 cup of shredded cheese.

  9. Toss the breadcrumbs with the remaining 2 tablespoons of melted butter and then sprinkle them over the casserole.

  10. Bake for 40 to 45 minutes, or until bubbly and lightly browned. Serve squash casserole hot.

Recipe Variations

  • Add chopped red peppers or green peppers with the onion, adding a little color as well as flavor.
  • You can spice it up by adding chiles as well.

Do You Peel Yellow Squash Before Cooking?

Yellow squash has a thin peel, similar to zucchini, and becomes very tender once cooked. Give the squash a scrub before cooking—no need to peel.

Can You Eat Yellow Squash Raw?

Yellow squash is safe to eat raw. It is best to use smaller squash for raw preparations and slice them thin or spiralize them for use in salads or other dishes. Yellow squash becomes milder and sweeter when cooked.

Can You Freeze Fresh Yellow Squash?

Before freezing yellow squash, it is best to blanch it first (cook quickly in boiling water) to remove some of the excess moisture. Drain well and vacuum seal or add to a zip-top freezer bag, expelling all of the air. Boil directly from frozen and use in your favorite casserole or other baked dish.