Zucchini Casserole

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Zucchini Casserole is a no-fuss dish that is delicious as a vegetarian entrée or a side dish for any meal.

This recipe is very simple, calling for just three main ingredients, zucchini, tomatoes, and a touch of onion. Adding a crunchy Panko breadcrumb topping with parmesan cheese gives for the perfect finishing touch. Zucchini really is the main star of this dish!

close up of a baked Zucchini Casserole

A Versatile Casserole Recipe

Easy Baked Zucchini has been a go-to side dish for us forever. It’s effortless and so delicious. I wanted to create a zucchini casserole that was light but flavorful and made the veggies the star of the dish (and not loaded down with bread etc).

ingredients to make a Zucchini Casserole

Ingredients

ZUCCHINI
The zucchini for this recipe doesn’t need to be peeled (or salted).  Simply rinse and slice.

TOMATOES
I like using Roma tomatoes in this recipe, they add great flavor but hold up well to baking and aren’t watery. You can use any ripe tomato, try to choose one with a similar diameter to the zucchini you’re using.

TOPPING
I love a crisp topping over this casserole. A combination of panko bread crumbs and parmesan cheese is the perfect addition. Fresh herbs are added after baking for lots of flavor.

vegetables on a cutting board with crumbs to make Zucchini Casserole

This baked zucchini casserole goes well with simple summertime fare and makes a nice substitute for a tossed salad. Serve it with grilled chicken breasts, hamburgers, or sausages.

How to Make Zucchini Casserole

  1. Cook onion in olive oil until tender. Toss zucchini with olive oil and seasonings.
  2. Alternate zucchini and tomatoes in a casserole dish (similar to how you would stack a ratatouille). Bake 20-25 minutes.
  3. Prepare topping & sprinkle over top.
  4. Bake until veggies are soft & topping is golden brown!

top view of Zucchini Casserole without crumbs

Tips for Casserole

  • Zucchini casserole tastes best eaten fresh from the oven. Because zucchini is so watery, it really doesn’t take very well to freezing. You’re likely to find it becomes just too mushy to be appetizing.
  • If you want your veggies softer but your topping is browned, loosely place a small square of foil over top to keep it from browning too much.
  • Leftovers can be refrigerated for up to 3 days and reheated in a microwave.

close up of a spoon taking a portion out of a Zucchini Casserole

More Summer Favorites

Did you enjoy this Zucchini Casserole? Be sure to leave a comment and a rating below!

close up of a baked Zucchini Casserole
5 from 21 votes
Review Recipe

Zucchini Casserole

Prep Time 25 minutes
Cook Time 45 minutes
Total Time 1 hour 10 minutes
Servings 8 servings
Author Holly Nilsson
This is a great way to use your zucchini straight from the garden! It's perfect as a low carb side dish option. 

Ingredients

  • 1 pound Roma tomatoes sliced ¼”
  • 1 ½ pounds zucchini sliced ½”
  • ½ teaspoon Italian seasoning
  • 1 ½ tablespoons olive oil
  • 1 clove garlic minced
  • for serving fresh basil and parsley
Topping
  • 1 tablespoon olive oil
  • 1/2 onion finely chopped
  • 1/4 cup bread crumbs
  • 2 tablespoons butter melted
  • ¼ cup fresh parmesan cheese
  • cup shredded mozzarella cheese

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Instructions

  • Preheat oven to 375°F.
  • Cook onion in olive oil (for the topping) until tender, about 5 minutes. Set aside.
  • Slice tomatoes and place on paper towels to absorb liquid, about 2-3 minutes.
  • Combine zucchini, Italian seasoning, olive oil and garlic in a bowl. Toss well and season with salt and pepper.
  • Alternate zucchini and tomatoes in stacks. Place the stacks on their sides in a 2 ½ qt baking dish or 9x13 pan. Cover with foil and bake 25 minutes.
  • Meanwhile, combine all topping ingredients in a small bowl (including onions from in step 1) and mix well.
  • Remove foil from casserole and top with topping. Bake uncovered an additional 20 minutes or until zucchini is tender.
  • Sprinkle with fresh herbs and serve warm.

Recipe Notes

Optional:  Spread a thin layer of tomato sauce (or pasta sauce) over the bottom of the casserole dish before adding the zucchini/tomato mixture.
For softer zucchini, cut thinner.
This makes a large dish. This recipe can be halved and baked in a 9x9 casserole dish.

Nutrition Information

Serving: 1cup, Calories: 84, Carbohydrates: 6g, Protein: 2g, Fat: 5g, Saturated Fat: 2g, Cholesterol: 9mg, Sodium: 103mg, Potassium: 295mg, Fiber: 1g, Sugar: 3g, Vitamin A: 475IU, Vitamin C: 22.6mg, Calcium: 60mg, Iron: 0.7mg

(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)

Keyword best Zucchini Casserole recipe, How to make Zucchini Casserole, squash casserole, zucchini casserole
Course Side Dish
Cuisine American

Got Zucchini?

Zucchini Casserole close up in a casserole dish with a title
Zucchini Casserole in a casserole dish and plated baked dish with writing
Zucchini Casserole with a spoon taking a portion out with writing
close up of Zucchini Casserole and a spoon with writing
About the author

Holly

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Holly is a wine and cheese lover, recipe creator, shopping enthusiast and self appointed foodie. Her greatest passion is creating in the kitchen and making deliciously comforting recipes for the everyday home cook!

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Recipe Rating




Comments

  1. This recipe is awesome! I brought it to a party and it was loved by everyone..This recipe is a keeper!5 stars

  2. Just made this today, it was delicious I did use your tip to use a small can of tomato sauce in the bottom of the dish. My SO isn’t fond of zucchini or cooked tomatoes, but likes fresh tomatoes and he really liked this dish.
    5 stars

  3. This recipe has been updated for better results, but we have been asked for the original recipe. Here it is!
    ¼ cup onion, finely chopped
    1 Tablespoon olive oil
    1 ½ pounds zucchini
    ½ teaspoon Italian seasoning
    1 ½ cups cherry tomatoes, whole
    salt & pepper to taste

    Topping
    ½ cup panko bread crumbs
    2 Tablespoons butter
    ¼ cup fresh parmesan cheese
    1 Tablespoon fresh parsley
    1 Tablespoon fresh basil

    1) Preheat oven to 350F.
    2) Heat a large skillet over medium heat. Cook onion in olive oil until tender, about 5 minutes.
    3) Slice zucchini ½” thick. If you prefer softer zucchini, cut thinner.
    4) Add zucchini and Italian seasoning. Cook an additional 3-4 minutes until just slightly softened.
    5) Place zucchini in a 2 quart casserole dish. Add in cherry tomatoes. Season with salt and pepper.
    6) Combine all Topping ingredients in a small bowl and mix well. Sprinkle over zucchini mixture.
    7) Bake casserole 30-35 minutes or until zucchini reaches desired doneness.

  4. This recipe looked and tasted amazing! Great side dish recipe for any occasion. I adjusted the fat content as I am on a low fat diet and it still had lots of flavour. I also used a large zucchini from a friend’s garden and cut the bigger slices in half to arrange in dish with tomatoes. This recipe is a keeper and will make again for sure!5 stars

  5. Yes, thank you for letting us know, I appreciate it! The print should be working now. Enjoy the recipe!

  6. Typically, this goes the French name of Ratatouille. I, personally add large mushroom caps sliced as a layer, and shredded cheese (gruyere is fabulous, provolone, etc.) on top!5 stars

  7. Holly, just wanted to let you know that the printout of this recipe doesn’t match what I see on the screen. Here on your website, you say: Mix the sliced zucchini with a minced clove of garlic. Slice the tomatoes, and allow the liquid to drain on a paper towel. Alternate zucchini and tomato slices, cover the pan with foil, bake for 30 minutes. Then you tell us to add the sauteed onion to the topping, sprinkle the topping over the zucchini & tomato slices, and bake uncovered another 20 minutes. I had that in my head, but when I made the dish a few days later, I went by the printout recipe. I followed the recipe. No garlic was listed. The cherry tomatoes were kept whole. The zucchini and onion were cooked together. Everything was then put in a casserole (zucchini, onion, and whole cherry tomatoes), topping was sprinkled on top. NO foil; bake for 30-35 minutes. But after 15 minutes, I checked the topping, and it was getting pretty brown. So I’m now doing the last 15 minutes with foil on top of my dish. It sure smells good, and I’m sure it will taste great, but the recipe I used is NOT what I see before me.

    1. I apologize for the inconvenience. We were having trouble with the printed versions showing the updated version for a couple of hours on July 27. It has been fixed and should print the correct version now. I hope your casserole was delicious.

  8. How many cups of sliced zucchini is the 1 1/2 lbs.? …..4 cups sliced?…And I purchased the items for this recipe before it was updated . Can I still use the mini tomatoes? Or should they be in equal size to the sliced zucchini?… meaning the Roma’s
    Thanks

    1. 1 ½ pounds is approximately 5 heaping cups of sliced zucchini. The zucchini casserole recipe itself was not updated. We do recommend that you use tomatoes similar in size to the zucchini. Hope that helps, Debra!

  9. The photo and introduction look and sound great, but they don’t seem to match up with the printed directions. The intro talks about plum tomatoes, the recipe about cherry. In addition, the intro has you alternating slices of zucchini and squash yet the recipe has you first adding all the zucchini and then the tomatoes on top. Can you explain the discrepancies? Actually, both ways sound yummy.

    I only discovered your blog last week and have already made one recipe–and loved it–and have plans to make a couple more this week. So glad I found you!!

    1. I apologize for the confusion, the recipe was recently updated for improved flavor and texture and the updates were not displaying. The post has been updated.