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+ servings
A squash casserole recipe with yellow squash and zucchini and a breadcrumb and Parmesan cheese topping.
5 from 14 votes

Healthy Summer Squash Casserole

Healthy, simple, and fabulous, this Zucchini and Squash Casserole is the best low-carb recipe for Summer squash! This easy casserole is amazing for Summer picnics and potlucks, and makes the perfect side dish for any holiday dinner!

Course Side Dish
Cuisine American
Prep Time 15 minutes
Cook Time 35 minutes
Total Time 50 minutes
Servings 6 servings
Calories 112 kcal


  • 2 lbs. summer squash zucchini and yellow squash, cut into ¼-inch slices
  • 2 ½ Tbsp. olive oil
  • 1 ¼ tsp. salt divided
  • ½ tsp. pepper
  • cup Parmesan cheese* grated
  • cup Panko breadcrumbs gluten-free
  • ¼ tsp. garlic powder
  • 2 Tbsp. fresh parsley finely chopped


  1. Preheat oven to 350 degrees.
  2. Cut yellow squash and zucchini into thin, ¼-inch slices.
  3. Sprinkle ½ teaspoon salt over the zucchini and squash slices. Let sit for 10 minutes and then dab to remove excess moisture with a paper towel.

  4. Spray a 9-inch square baking dish with non-stick cooking spray.
  5. Alternatively, overlap the zucchini and squash in a row. (See pictures.) You should be able to form 4 rows.**

  6. Drizzle olive oil over the zucchini and squash and then sprinkle with salt and pepper.
  7. In a small bowl combine Parmesan cheese, breadcrumbs, and garlic powder. Toss to combine and then sprinkle over the zucchini and squash.

  8. Cover baking dish with aluminum foil and bake in preheated oven for 30 minutes.
  9. Remove foil and turn heat to a High broil. Broil for an additional 5-7 minutes, or until breadcrumb topping starts to turn a golden brown.
  10. Serve immediately with fresh parsley and enjoy!

Recipe Video

Recipe Notes

*Can use a vegan Parmesan cheese substitute.

**I like to get small-medium, similarly-sized summer squash so they will be able to fit into four rows easily!

Expert Tips and Tricks

  • Use a mandoline. This gives you the most precise slices so they all cook at a similar rate.
  • Sprinkle a little salt to prevent to soggy mess. Let the salted squash sit, then blot dry. The salt releases excess moisture.
  • Try out Italian breadcrumbs. Since they're pre-seasoned, you will have to adjust the other seasoning ingredients.
  • Broil it at the end. This gives it a great crunchy topping.
  • Use all of one squash - If it's all you have, either use all zucchini or all yellow squash.

Meal Prep and Storage

  • To Prep-Ahead: Follow all directions but wait to bake until you're ready to serve. Cover tightly with foil and refrigerate for up to 2 days. Bring to room temperature and bake according to directions.
  • To Store: If there happen to be leftovers, store in an airtight container in the refrigerator.
  • To Reheat: Preheat your oven to 300°. In an oven-proof dish bake for 10-12 minutes or until heated through. You can also broil the casserole again for 1-2 minutes to bring back some of that crunchy topping.

Nutrition Facts
Healthy Summer Squash Casserole
Amount Per Serving
Calories 112 Calories from Fat 72
% Daily Value*
Fat 8g12%
Saturated Fat 2g13%
Cholesterol 4mg1%
Sodium 602mg26%
Potassium 410mg12%
Carbohydrates 8g3%
Fiber 2g8%
Sugar 4g4%
Protein 4g8%
Vitamin A 450IU9%
Vitamin C 27.4mg33%
Calcium 96mg10%
Iron 0.8mg4%
* Percent Daily Values are based on a 2000 calorie diet.