Parmesan Squash Casserole

4.96 from 43 votes
70 Comments

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This Parmesan Squash Casserole recipe is the perfect way to use up all that squash and zucchini from the garden. Seasoned with fresh herbs and cheeses, this is a delightful side dish to any meal.

Yellow squash, zucchini, and tomatoes layered in a white casserole dish.

Yellow Squash and Zucchini Casserole

This Parmesan Squash Casserole is one of my favorite ways to use up our abundance of squash and zucchini in the garden. Beautiful green, yellow and red colors create a vibrant side dish that complements many main meals and my kids love all the cheese layered in this glorious casserole. Plus, it’s so easy to make! You don’t even need to layer everything in like in the picture. Most of the time I just throw all the ingredients in the baking dish since it all tastes the same and it takes less time. I only do the layered look when I am serving it to guests or taking it to a potluck.

Ingredients in Parmesan Squash Casserole

  • yellow squash (summer squash)
  • zucchini
  • olive oil
  • minced garlic
  • fresh thyme leaves or dried thyme
  • tomatoes
  • large eggs
  • sour cream
  • crumbled feta – (if you don’t like feta you can sub for another cheese like cheddar cheese or mozzarella)
  • grated parmesan cheese
  • lemon juice
  • salt and pepper

Other Ingredient Options

Health Benefits of Zucchini and Squash

Besides looking beautiful, zucchini and squash are high in water and fiber. They’re chock full of good things like riboflavin, folate, Vitamin C and potassium. The bottom line is, they’re super good for you! And since they have a mild flavor, you can spice them up a million different ways. You can keep the calorie count low by seasoning them up with salt and pepper and roasting them in the oven, grilling them outside or chopping them up and throwing them in salads. Of course, I like to follow the moderation in all things mantra, so my favorite way to enjoy these veggies is to layer them with cheese and bake. The possibilities are endless!

Zucchini and squash sliced in a white casserole with a silver spoon with squash on it.


Add A Cracker Crumb Topping (Optional)

If you prefer your squash casserole to have a crispy buttery cracker topping, you can add some crumbled Ritz crackers or some seasoned bread crumbs over the top before baking. Simply mix about 1 cup of Ritz cracker crumbs (aka buttery round crackers) with ¼ cup grated parmesan cheese and 3 Tablespoons of melted butter. Mix until crumbly and then spread over the top of the squash mixture and bake.

What to Serve with Squash Casserole

This casserole recipe is a perfect side to so many meals. Here are a few of our favorite pairings:

Rave Reviews for this Squash Casserole Recipe

We are so happy to know this recipe has become a family favorite for many of our readers. Please see the comments below. It really is a crowd-pleaser! It’s been fun to see how fabulous cooks have made substitutions to make it fit the likes and dislikes of the family. One cook said she omitted the tomatoes and replaced it with sausage and it was a hit! This is a recent review we were thrilled to receive:

“I am the Food Service Director at a Senior Living Community. We have a farm to table program and I was looking for something to use my squash, zucchini and tomatoes. I had a big Block Party event and I wanted to showcase our farm to table dishes. My cooks made this casserole and we ran out of it before we ran out of the Brisket! I must have had 10 people ask me for the recipe. I’m quite seriously thinking about this becoming our “signature” dish!
We’re making more tomorrow for the staff because it was such a hit. Thanks!” – Donna

Zucchini and squash in a casserole dish with cheese melted on top.

Frequently Asked Questions

How do I keep my squash casserole from getting watery?

By tossing the squash in a little salt before sautéing, some of the moisture from the squash will naturally be removed. You can also remove the squash from the skillet after lightly sautéing and pat the squash dry with a paper towel.

Is squash casserole healthy? Keto?

As this recipe is made, this dish can be considered Keto-friendly. It is low carb with no added sugars. It is also gluten free!

What kind of squash is best?

We use yellow squash, crookneck or Summer varieties, and zucchini for this recipe.

What should I do with leftovers?

Store leftover casserole in an airtight container in the refrigerator.

READ NEXT: Spaghetti Casserole

More Delicious Squash Recipes

Looking for more recipes to help you use up that extra garden squash and zucchini? Give these a try:

How to Make Parmesan Squash Casserole

Yellow squash, zucchini, and tomatoes layered in a casserole dish.

Parmesan Squash Casserole

4.96 from 43 votes
Parmesan Squash Casserole is a perfect way to use up all that squash and zucchini from the garden. Seasoned with fresh herbs and cheeses, this is a delightful side dish to any meal.
Prep Time 15 minutes
Cook Time 45 minutes
0 minutes
Total Time 1 hour
Course Side Dish
Cuisine American
Servings 10 servings

Video

Ingredients

  • 4 yellow squash and/or zucchini (about 8 cups sliced)
  • 1 tablespoon olive oil
  • 1 tablespoon minced garlic
  • 1 tablespoon fresh thyme leaves or ½ tsp dried thyme
  • salt to taste
  • 2 tomatoes sliced
  • 2 eggs
  • 1/3 cup sour cream
  • 1 cup crumbled feta not tightly packed
  • 2 tablespoon grated parmesan cheese
  • 1 tablespoon lemon juice
  • salt and pepper

Instructions

  • Preheat oven to 375 degrees and spray a large casserole dish with nonstick spray. Slice the squash into 1/4" slices. If they are larger squash, cut them down the middle before slicing.
    Yellow squash being sliced on a cutting board.
  • Heat oil in a large non-stick frying pan. Add the squash, garlic, thyme, and salt to taste. Sauté and stir until the squash is just starting to soften. Don't overcook!
    squash and zucchini in a skillet with thyme and garlic
  • Remove from heat and add tomatoes.
    Squash, zucchini, and tomatoes being cooked in a skillet.
  • Beat together the eggs, sour cream, cheeses, and lemon juice in a medium sized bowl.
    Feta cheese and eggs being mixed in a bowl.
  • Place half of the squash into the bottom of the casserole (you can be fancy and layer it like in the picture or you can just toss it in).
    Squash, zucchini, and tomatoes in a single layer in a baking dish.
  • Sprinkle on some salt and pepper then spread ½ of the egg mixture over the top. Repeat with remaining squash and egg mixture. Top with additional feta and Parmesan if desired.
    A casserole dish with vegetables with an egg mixture poured over the top.
  • Bake for 40-45 minutes, until the mixture is bubbling and slightly set. Serve hot.
    Parmesan squash casserole with a silver spoon.

Notes

Add A Cracker Crumb Topping (Optional)

  • If you prefer your squash casserole to have a crispy topping, you can add some crumbled Ritz crackers or some seasoned bread crumbs over the top before baking.
  • Simply mix about 1 cup of crumbled Ritz crackers (aka buttery round crackers) with ¼ cup grated parmesan cheese and 3 Tablespoons of melted butter.
  • Mix until crumbly and then spread over the top and bake.

Nutrition Information

Calories: 99kcalCarbohydrates: 5gProtein: 5gFat: 7gSaturated Fat: 3gCholesterol: 50mgSodium: 204mgPotassium: 306mgFiber: 1gSugar: 3gVitamin A: 540IUVitamin C: 18.6mgCalcium: 119mgIron: 0.7mg

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About the author

Erica Walker

Erica lives in Boise, Idaho with her husband, Jared, an attorney, and her three beautiful girls. Beyond the world of recipes, she loves adventuring with everything from kayaking, to cruising, to snowboarding and taking the family along for the thrill ride.

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4.96 from 43 votes (19 ratings without comment)

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Comments

  1. 5 stars
    Delicious way to use squash. I added an onion in with the squash, and topped it with the crumbled butter crackers.

  2. 5 stars
    Thank you so much for sharing this amazing parmesan squash and zucchini bake recipe! Will surely have this again! It’s really easy to make and it tasted so delicious! Highly recommended!

  3. 4 stars
    This didn’t work right for me. Wasnt enough of the egg/cheese mixture to hold it together, and a ton of water came out of the veggies, even cooking a but longer than it called for. I’ve read you can salt the vegies before to get some of the water out, would definitely recommend trying that. The flavor was nice but needs some tweaking for me personally.

  4. I will make this recipe tonight my only question is from the picture it looks like you sliced the squash lengthwise not crosswise, is that right?

  5. 5 stars
    It’s remarkable to go to see this site and reading the views of all
    mates about this article, while I am also eager
    of getting know-how.

  6. Hello so I am making this for football tomorrow and I was wondering if I could prepare it in a way to where I could do all prep and put together and cook it in the morning ? Would you suggest this or not ? Thank you

    1. Unfortunately, this isn’t a recipe I would recommend making ahead of time. I would worry about everything getting soggy. Sorry!

  7. 4 stars
    Hi! I made this recipe exactly like it stated except I used all zucchini. It was good tasting, but didn’t look like the picture. People liked it, but didn’t rave about it. I’m sure I did something wrong. The only thing I can think of is I used a hand mixer to “beat” the egg mixture. It was very watery and I really couldn’t spread the mixture, more like pour it over the tomatoes. The casserole was very watery and it wasn’t cheesy, even though I put a layer of parmesan on top. What did I do wrong?

    1. Hmm, the only thing I can think of is that the other vegetables have a different water content than the zucchini and so omitting them might have caused the sauce to be more watery. I’m sorry it didn’t turn out!

  8. 5 stars
    I have made this recipe twice and my family loved it. I had to omit the tomatoes because of diet restrictions. The second time I made it, I crumbled some spicy Italian sausage on top of each layer. I double the recipe because I’m feeding a big family and it is hard to have any leftovers. I’m making it again tonight and at the request of my crew, I’m going to add a bottom crust. My husband says he could eat it every night. Lol, I told him to be careful what he wishes for as our garden is producing more than we can eat and share.
    Thank you for this recipe! I am passing it on to my friends and family.

  9. Hi! I have a large container of sliced yellow squash that is currently frozen. Could I use that? Worried that it might be too watery. Maybe let it completely thaw and pat dry first? Thanks for your thoughts!

    1. I haven’t tried it that way, but it sounds delicious! Let us know how it turns out if you try it!

      1. Can you suggest a substitution for the feta cheese? I dislike it quite a lot, but the rest of the recipe sounds delicious!!

  10. 5 stars
    I am the Food Service Director at a Senior Living Community. We have a farm to table program and I was looking for something to use my squash, zucchini and tomatoes. I had a big Block Party event and I wanted to showcase our farm to table dishes. My cooks made this casserole and we ran out of it before we ran out of the Brisket! I must have had 10 people ask me for the recipe. I’m quite seriously thinking about this becoming our “signature” dish!
    We’re making more tomorrow for the staff because it was such a hit. Thanks!

    1. Hi Abbey- Wow what a huge compliment! I am so glad that you (and your guests) enjoyed this dish so much! This is the perfect time of year to make it too, I bet it was extra delicious using all your fresh garden vegetables. Thanks for the nice comment and for the 5-stars!

    1. We haven’t made this ahead of time, so I’m not sure. I don’t know how freezing would change the texture of the veggies.

    1. I agree this recipe sounds amazing I really appreciate the nutrition content that you put in and the suggestions for the sides awesome idea 8ooo 5

    1. That’s a good question because the eggs kind of hold everything together. One source I found online says: Mix together one heaping Tablespoon of soy flour and 2 Tablespoons water per egg. Maybe that will help? Let me know if either of these suggestions work!

  11. Don’t have sour cream I usually use Greek yogurt substitute….what’s your opinion with this dish?

  12. I was going to half the recipe but wanted to check. It says 4 squash and/or zucchini. Is that 2 of each or 4 of each? Thanks!

  13. I was thinking of making this for Thanksgiving but don’t want to wait until the day of to prepare. Can this be made ahead of time and then popped in the oven to bake a day or so later?

    1. We haven’t done it that way before but you might be ok. the only thing I would be worries about it the egg.. it might not be ok for the egg to sit in the fridge longer than a day. Let us know if you make it beforehand and how it turns out!

  14. 5 stars
    This is a tad laborish to prep but well worth it! I did sprinkle the top with Italian Bread Crumbs followed by more parm cheese before baking. Fun change up! Thanks.

    1. You can use either banana squash or crookneck squash – they are both yellow and have similar textures and tastes. Thanks for asking!

  15. Do you know how many calories are in this dish? FYI…. it was AMAZING!!!! I added fresh mushrooms and chicken and loved it. Thank you!!!

    1. I honestly have no idea, if you use a calorie calculator like Livestrong.com or one like it, you could probably get a close estimation. Glad you liked it!!!

  16. 5 stars
    Made it tonight. I had part of a cauliflower, a few fresh mushrooms, 1/2 of a freshly picked tomato and some Vidalia onion that I added to the freshly picked zucchini and yellow squash. I also used Mexican Crema instead of sour cream – also a bit of curry powder. Great casserole! So versatile and a great way to use beautiful summer veggies! Thank you!

  17. 5 stars
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