Parmesan Squash Casserole is topped with breadcrumbs.

Momma Betty's Parmesan Squash Casserole

My mother-in-law's Squash Casserole is awesome. It's a delicious, creamy way to get everyone to eat squash. 

Course Main Course
Cuisine American
Keyword sauash casserole, baked squash casserole, parmesan squash, baked squash
Prep Time 10 minutes
Cook Time 30 minutes
Total Time 50 minutes
Servings 8
Calories 391 kcal
Author Lois Carter Crawford / Recipe Idea Shop inspired by Betty Lambdon Crawford


  • 1-1/2 pounds fresh yellow squash can also use zucchini
  • 1/2 cup chopped onion
  • 1 Tablespoon olive oil
  • 1 cup shredded Parmesan or Pecorino Romano cheese
  • 1 cup mayonnaise
  • 2 eggs
  • 1/4 teaspoon pepper
  • 1/8 teaspoon salt
  • 2 Tablespoons butter can substitute olive oil
  • 3/4 cup Italian bread crumbs or 3/4 cup cornflake crumbs and 1/2 teaspoon Italian Seasoning


  1. Sauté the onion and squash in a little olive oil until the onions are translucent.

  2. Drain well.

  3. Combine squash with mayonnaise, cheese, eggs, salt and pepper.

  4. Pour into a greased casserole dish.

  5. Melt butter and mix with bread crumbs (or cornflake crumbs, for gluten-free) until crumbly.

  6. Sprinkle on top of casserole.

  7. Bake 30 minutes at 350 degrees or until the custard sets.