Healthy Zucchini & Squash Casserole Recipe

A healthy squash casserole recipe that is made with yellow squash, zucchini, a crunchy breadcrumb and Parmesan topping and then baked in the oven to crispy perfection!  This easy baked casserole is a wonderful side dish recipe to serve up for summer picnics or at your Thanksgiving table!

Want other zucchini and summer squash recipes?  You might also enjoy this Sauteed Zucchini and Squash, Oven-Roasted Vegetables, and these Zucchini Lasagna Roll-Ups.

Squash Casserole Recipe

Zucchini and yellow squash are some of the overlooked vegetables that somehow magically reappear during the summer months and at a Thanksgiving table.

I first discovered my love of cooking with this delightful combo when Cohl started coming home with enormous bags full of fresh summer produce from a fellow dentist at his office a few years ago.

After making a few batches of this Sauteed Zucchini and Squash, I started to run out of new recipe ideas.

Easy Baked Casserole

One week Cohl came home and the bag was packed to the brim with yellow summer squash and zucchini.

It would be a sin to let them all go bad, so I had to brainstorm a new summer recipe.

Squash casserole has always been one of my favorite summertime side dishes.

This time I wanted to try to make a healthier version that was still simple to make and baked in the oven.

Ingredients

Sure, the cheesy and cream-laden squash casseroles taste ah-maaazing, but let’s be real… all of that dairy takes away the incredible flavor of the fresh vegetables!

The ingredients for this recipe are pretty simple.  You probably have most of them in your kitchen already:

• Zucchini and Yellow Summer Squash – Feel free to use all yellow squash or all zucchini if that happens to be what you have.  However, I think the alternating colors are what make this casserole so unique and pretty!
• Olive oil – You can also use any other type of healthy oil you happen to have on hand that does not have a ton of flavor.  Avocado oil, safflower, and sunflower oil will all work equally as well.
• Garlic Powder – The secret ingredient that gives this dish a unique flavor!
• Salt & Pepper – You can adjust these to your personal taste preferences.
• Parmesan cheese – Regular, dairy-filled, Parmesan cheese is my preference, but feel free to use a vegan and dairy-free Parmesan cheese, too.
• Panko Breadcrumbs – You can use regular breadcrumbs or gluten-free breadcrumbs. The taste will be minimally affected.

Cook’s Tip: Make sure you do not get a seasoned breadcrumb mixture as this will largely affect the taste of your casserole!

• Parsley – Not absolutely necessary but makes the casserole really pretty when serving.

How to Make

As I mentioned previously, this recipe is not only healthy, but it is also extremely easy to make.

Step-by-step Instruction:

1. Preheat oven to 350 degrees.
2. Prepare yellow squash and zucchini by cutting into 1/4-inch slices.
   1. You can either do this by carefully using a mandoline or with a sharp knife.
3. Sprinkle 1/2 teaspoon salt over all of the slices and let sit for 10 minutes.  Wipe away any excess moisture that forms with a paper towel.
4. Layer the zucchini and yellow squash in a 9-inch square baking dish and sprinkle with remaining salt and pepper.
5. Whisk together breadcrumbs, Parmesan cheese, and garlic powder.  Sprinkle over zucchini and squash.
6. Cover baking dish with aluminum foil and bake in preheated oven for 30 minutes.  Broil for 3-5 minutes or until the topping becomes crispy.

Tip: Crispy Casserole Topping

Normally yellow squash and zucchini release A LOT of moisture when baked in the oven.

In order to let them release the majority of their moisture content BEFORE baking it in the oven, you will need to sprinkle a bit of salt over the prepared slices.

This simple step allows the sliced zucchini and squash to release a large amount of the water they retain and will help you to get a crispy, and not soggy!, casserole.

Prep-Ahead Tips

You totally can prep-ahead and have this side dish ready-to-go when you are.  This is especially handy when it comes to preparing a healthy casserole for a backyard BBQ, picnic, or Thanksgiving day.

Prep-Ahead Steps:

1. Prepare the recipe until it is time to bake it.
2. Wrap the baking dish with aluminum foil and refrigerate up to 2 days until you are ready to eat.
3. Let the casserole come to room temperature and pick up on the recipe where you left off!

Store & Reheat

Chances are you won’t have many leftovers at all of this summer squash recipe.  But if you do, the best way to store it is in the pan you cooked it in OR you can place it in a tupperware container.

When ready to reheat, simply preheat your oven to 300 degrees, place it in a baking dish, and 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.

Other Healthy Summer Squash Recipes:

Baked Parmesan Zucchini Fries

Thai Zucchini Noodle Salad with Cabbage

Zucchini Lasagna Roll-Ups | Keto, Low-Carb

Baked Zucchini & Squash

More healthy side dish recipes.

3.78 from 97 votes

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Healthy Summer Squash Casserole

Healthy Squash Casserole recipe that is made with yellow squash, zucchini, a crunchy breadcrumb and Parmesan topping and then baked in the oven to crispy perfection! 

Course Side Dish

Cuisine American

Keyword baked, gluten free, healthy, oven

Prep Time 15 minutes

Cook Time 35 minutes

Total Time 50 minutes

Servings 6 servings

Calories 112 kcal

Author London

Ingredients

• 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

• ⅓

  cup. Parmesan cheese* grated
• ⅓ cup. Panko breadcrumbs gluten-free
• ¼ tsp. garlic powder
• 2 Tbsp fresh parsley finely chopped

Instructions

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!

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.