This post may contain affiliate links. See our disclosure policy.
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 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
- oregano
- parsley
- basil
- onions (white or yellow onion)
- cream of mushroom soup
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!
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:
- Instant Pot Pork Chops and Gravy
- Chicken Parmesan
- Easy Cheesy Manicotti
- Herb Crusted Salmon
- Parmesan Herb Baked Mahi Mahi
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
Frequently Asked Questions
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.
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!
We use yellow squash, crookneck or Summer varieties, and zucchini for this recipe.
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 Cook Yellow Squash – 4 Easy Ways
- Oven Roasted Vegetables
- How to Cook Spaghetti Squash – 4 Easy Methods
- Pasta Primavera with Chicken
How to Make Parmesan Squash Casserole
Parmesan Squash Casserole
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.
- 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!
- Remove from heat and add tomatoes.
- Beat together the eggs, sour cream, cheeses, and lemon juice in a medium sized 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).
- 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.
- Bake for 40-45 minutes, until the mixture is bubbling and slightly set. Serve hot.
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.
Delicious way to use squash. I added an onion in with the squash, and topped it with the crumbled butter crackers.
What a cheesy, tender, & delicious side dish!! Definitely a great way to use up those veggies!!
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!
Absolutely loved this casserole! Thank you.
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.
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?
No, we cut them crosswise!
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.
Thank you!
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
Unfortunately, this isn’t a recipe I would recommend making ahead of time. I would worry about everything getting soggy. Sorry!
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?
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!
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.
Oooh I never thought of adding sausage! That sounds delicious! Thanks for sharing!
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!
I think if you thaw it and pat it dry it should be fine!
What other cheese can be used instead of feta and also any other spice to replace the thyme?
I would suggest using ricotta cheese and basil! Hope this helps!
Can I add sliced potatoes to this recipe?
I haven’t tried it that way, but it sounds delicious! Let us know how it turns out if you try it!
The best casserole I’ve ever had. This one is a keeper.
Thank you, Kathy! It really is one of our family favorites – especially this time of year.
Can you suggest a substitution for the feta cheese? I dislike it quite a lot, but the rest of the recipe sounds delicious!!
You can just add more parmesan cheese!
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!
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!
This is incredibly good! So tasty with the addition of cheese! Love it!
I’m a squash fan! The cheese and spices in this recipe were amazing. Loved it!
What a delicious way to use up my summer veggies! This looks amazing!
This is a great way to use up the end of summer produce!
Perfect summer casserole! My family LOVES this recipe!