Crispy Zucchini Casserole

Summer side dishes don't get better than this zucchini casserole recipe! A crispy, nutty panko topping covers a saucy layer of pesto and zucchini.

Zucchini Casserole Recipe

If you have a mountain of zucchini or yellow squash in your fridge, this zucchini casserole recipe is just the thing for you! In fact, you should try this recipe even if you don’t have any summer squash on hand. The crispy, nutty Parmesan and panko topping contrasts perfectly with the saucy zucchini, pesto, and marinara underneath. It’s super simple to put together, and it can pass as a side dish or a meal on its own. Make this zucchini casserole recipe once, and you’ll have it on repeat all summer long.

Sliced zucchini

Zucchini Casserole Recipe Ingredients

Here’s what you’ll need to make this delicious zucchini casserole recipe:

  • Fresh zucchini, of course! I actually like to use a mix of yellow squash and zucchini in this recipe, but just one or the other would work fine too.
  • Yellow onion – It gives the veggies a savory depth of flavor.
  • Basil pesto – I toss it with the zucchini and onion for richness and fresh, nutty flavor.
  • Marinara sauce – Tomatoes+basil are a match made in heaven, so I couldn’t resist adding tomato sauce to this dish! It helps make the middle of the casserole saucy and bubbly as it bakes.
  • Panko bread crumbs and Parmesan cheese – Together, they create a crispy, savory topping for the saucy squash and onions. I like to turn the broiler on for the last few minutes of baking to get them brown and crisp!

Toss the zucchini slices and onions with the pesto, and cover the bottom of a casserole dish with the tomato sauce. Pile in the veggies, and smooth them into an even layer. Sprinkle the panko bread crumbs and Parmesan cheese on top, and add a pinch of red pepper flakes and a drizzle of olive oil. Bake at 375 for about 25 minutes, until the topping is golden brown and the squash is tender. Enjoy!

Find the complete recipe with measurements below.

Zucchini and summer squash with pesto

Squash Casserole Recipe Tips

  • Slice the zucchini as evenly as possible. The more evenly you slice the zucchini, the more evenly it will bake. You don’t want thin slices to become mushy before thicker ones cook through! I recommend using a mandoline to make sure that your slices are all the same width.
  • Pat the zucchini dry. Zucchini can release a lot of water as it cooks! In order to keep your zucchini casserole from becoming watery, pat the zucchini dry before you toss it with the pesto. Better yet, set the sliced zucchini on a kitchen towel to drain while you prep the other ingredients.
  • Smaller squash = better squash. This cheesy zucchini casserole comes out best when it’s made with small, firm summer squash. Large zucchini have a tendency to be seedy and watery, so I don’t recommend using them here.
  • Make it vegan. This zucchini casserole is a great recipe to make vegan. Replace the traditional pesto with vegan pesto, and use my vegan Parmesan in the topping. Trust me, you won’t miss the cheese one bit!

Summer squash in a baking dish

Zucchini Casserole Serving Suggestions

This zucchini and squash casserole is a perfect side dish for 3-4 people. Serve it with your favorite protein, homemade pizza, or a simple pasta dish. I especially love it with these summer pasta recipes:

For more pasta recipes, check out this post!

Alternatively, make this zucchini casserole a meal on its own. Pile it on a bed of creamy polenta, cooked quinoa, or couscous, and add a handful of roasted chickpeas for a delicious, healthy dinner.

Zucchini and Squash Casserole

More Favorite Zucchini Recipes

If you love this zucchini casserole, try one of these zucchini recipes next:


5.0 from 2 reviews

Crispy Zucchini Casserole

 
Prep time
Cook time
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This zucchini casserole is the BEST summer side dish! To make this recipe vegan, replace the cheese with vegan Parmesan, and use vegan pesto instead of regular.
Author:
Recipe type: Vegetable
Serves: 3 to 4 as a side
Ingredients
  • 4 cups mixed zucchini and yellow squash, thinly sliced
  • ½ cup thinly sliced yellow onion
  • ½ cup basil pesto
  • ½ cup marinara sauce
  • ⅓ cup panko bread crumbs
  • ¼ cup grated Parmesan cheese
  • Pinch of red pepper flakes
  • Extra virgin olive oil, for brushing and drizzling
Instructions
  1. Preheat oven to 375°F and brush the bottom of a 9x12-baking dish with olive oil.
  2. Set the sliced squash on a kitchen towel to drain some of the excess moisture while you prep everything else.
  3. In a large bowl, toss the zucchini and onions with the pesto.
  4. Layer the baking dish with the marinara sauce, followed by the zucchini mixture. Spread the zucchini into one even layer.
  5. Sprinkle the top with the panko, Parmesan, a drizzle of olive oil, and pinches of red pepper flakes. Bake until the zucchini is tender (but not mushy) and the top is crispy and lightly browned - about 25 minutes. I like to turn my broiler on for the last few minutes to help the topping become browned and crisp.
  6. Remove from oven and let it cool 20 minutes before slicing.

 

38 comments

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Rate this recipe (after making it):  

  1. Bring on the zucchini! I love the crispy and baked parts of this, forces me to stray from my usual cutting and roasting!

  2. Eileen from hampiesandwiches.blogspot.com
    08.27.2014

    What a great way to eat up some of the massive late summer zucchini extravaganza! I love it. 🙂

  3. Elyse from lifewithoutlemons.com
    08.27.2014

    So simple and delcious! I have an abundance of courgettes (sorry just cant bring myself to call them zucchini yet!) Will certainly be trying this, thank you.

    • jeanine
      08.27.2014

      it’s ok, courgette is so much prettier 🙂

  4. I have zucchini coming out of my ears! I’m making this tonight, it looks great. Zucchini brownies for dessert too I guess (recipe on my site)!

    • jeanine
      08.27.2014

      mmm, sounds delish – love chocolate and zucchini together!

  5. Jessica
    08.27.2014

    Thanks for posting! I cook for a family of 5 and only one of us is Vegan, so when it comes to finding family-friendly vegan recipes I love your site! This is reminiscent of pizza for my brothers and they love it 🙂
    I replaced the cheese with some nutritional yeast instead, but I also wanted to try it with some cashew cheese too!

    • jeanine
      08.27.2014

      so glad you liked it! I love nutritional yeast, I’ll have to try that next time, thanks for the tip!

  6. Ella from youtube.com
    08.27.2014

    This sounds wonderful! I love pesto… I don’t think I’d be missing anything by vega-fying it 🙂 per the above comment, I might try with some nutritional yeast! Thanks for sharing!
    http://www.youtube.com/sparklesandsuch26

    • Elise
      09.16.2014

      I made it with nutritional yeast & it was as good as you’d think! Give it a try! I mixed the nutritional yeast in with the breadcrumbs.

  7. Bryan from thewanderinggourmand.com
    08.27.2014

    I need more understanding friends like you have. Mostly vegan and mostly gluten free would get me uninvited 🙂 Great recipe! Of course, I’m a gluten meat eater.

  8. This looks phenomenal! Simple, delicious, loads of veggies, and pesto – love it!

  9. Nicole B.
    08.27.2014

    I just had zucchini for the first time a few months back and became obsessed with it. My husband agrees that this really tasty. Pinned for future making!

  10. Meghan from oatgasm.blogspot.com
    08.28.2014

    This is almost a sort of inverted vegetable lasagna, simplified. I love it!

  11. Serena from theherbdiaries.com
    08.28.2014

    Yum that looks delicious – what great way to use courgettes. Can’t wait to try it! Gorgeous pictures as always

  12. Elizabeth from themotherhubbardscupboard.com
    08.28.2014

    I love new ways to use up Zucchini (Australian) as we always have an over abundance in the garden 🙂 Thanks for sharing! Liz x

  13. simple recipe with a lot of flavor.
    Love the zucchini series.. Cheers!

  14. Linda from doeskitchen.com
    08.29.2014

    Must make this – it looks delicious!

  15. sara from cupcakemuffin.blogspot.com
    08.30.2014

    This looks incredible! Wow – such a great dish!

  16. Paula
    09.03.2014

    Thank you so much for the recipe! But since it contains zucchini, my advice is to buy only veggies that are shorter than 8 inches because the longer ones can be bitter 🙁 A while ago I’ve noticed that some zucchinis are just more bitter than other and then I’ve found this explanation:
    http://www.listonic.com/protips/get/soeextwjle

  17. Sally
    09.03.2014

    What a great idea looks tasty 🙂

  18. Elise
    09.16.2014

    I made this last night & it did not disappoint! Even my boyfriend, who has a very pronounced distaste for zucchini & squash, went back for seconds. We were both blown away by the delicious layers of flavor & how healthy of a dish it is. I made it vegan & added cashews to the pesto instead of pine nuts then combined nutritional yeast with the breadcrumbs on top. We made half of the dish with breadcrumbs & half without – both were completely delectable.

    Thanks for a recipe that tastes as good as it looks! This would be a perfect potluck dish & I wish summer wasn’t almost over so I could keep making it!

    • jeanine
      09.17.2014

      I’m so glad you liked it – thanks for coming back to let me know! I’ll have to try it with nutritional yeast & breadcrumbs next time 🙂

  19. Meg
    10.20.2014

    Just threw this is the oven! Just some notes on the recipe – you never mention to toss the squash in with the pesto, it’s just referred to as “pesto-ed squash”, which was confusing. Also, you didn’t say what to do with the onions, which I didn’t realize until I’d already put the panko layer on top. I tried to squeeze them in under some of the zucchini, but had to leave out most of them. I’m excited to have it tonight, just thought I’d pass along a few critiques!

  20. Geneviève
    11.10.2014

    Just tried it tonight, it was delicious! I never though zucchini could taste that good!

    Merci!

  21. Agne
    09.22.2015

    I just love zucchini. I just always wanted to try something new. (till now i’m just making zucchini pancakes, bake them in the pan with batter and sprinkle with garlic anr parsley and sometimes make omelet with them) thank you for this recipe. This was reaaaaally tasty! will try something else!

    • jeanine
      09.22.2015

      so glad you liked this one too!!

  22. Shelley from shelleydell.com
    07.30.2016

    My son who is new to cooking made this today. It was pretty good. while we were cleaning up I noticed a pile of sliced onions on the counter! He took your suggestions to set the onions aside very seriously and did not add them to the zukes when he stirred in the pesto. I’m pretty sure that the onions would have been a great addition, you might want to edit the instructions for new and very literal cooks 😉

    • Jeanine Donofrio
      07.30.2016

      Hi Shelley, just fixed it – thank you for pointing that out!

  23. Sweta
    07.02.2017

    I just made this using stuff from the farmers market, and instead of making the pesto from scratch, I made the tomato sauce from scratch 🙂 It was really good!

A food blog with fresh, zesty recipes.
Photograph of Jeanine Donofrio and Jack Mathews in their kitchen

Hello, we're Jeanine and Jack.

We love to eat, travel, cook, and eat some more! We create & photograph vegetarian recipes from our home in Chicago, while our shiba pups eat the kale stems that fall on the kitchen floor.