Yellow Squash Casserole

November 19, 2019

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Yellow Squash Casserole – made with fresh yellow squash, a cheesy, creamy coating and it’s finished with crispy toasted panko bread crumbs. It’s a delicious, homestyle side dish that’s perfect for holidays, and a great way to use up the abundance of summer squash.

Yellow squash casserole in a white baking dish with one scoop removed to show filling.

Yellow Squash Casserole Recipe

I first made this casserole about 10 years ago and I’ve made it many times since! It’s the perfect thing to make for Thanksgiving and other dinner parties to add something new to the classics.

I used to make it with fresh bread crumbs but I’ve decided this classic southern style recipe is so much better with crisp, buttered panko.

Here you’ll love how the flavors of the cheddar and parmesan pair perfectly with the yellow squash. It takes an otherwise bland and boring squash casserole to another sort of decadence.

And then there’s a hint of garlic and fresh herbs to finish off all those satisfying flavors. It’s a must try, comforting vegetable side dish!

Cheesy squash casserole on a brown plate.

Ingredients Needed for Squash Casserole:

Yellow squash – you’ll need a lot for this recipe. It’s the main ingredient and star of the show.

Butter – salted or unsalted butter works fine here.

Yellow onion and garlic – these will add an extra layer of flavor to this tasty side dish.

Sour cream – you’ll love the creamy, lightly tangy flavor this adds. I recommend sticking with full fat to keep it rich.

Egg – this just help bind things together a bit.

Panko – this is used both in the filling (to soak up some of the extra moisture), and as a topping. Because who can resist that fine crispy crunch?

Sharp cheddar cheese and parmesan cheese – yellow or white cheddar will work great here. Skip powdery grated parmesan.

Fresh parsley and dried chives – these add a light herby flavor to the dish. I like to use freeze dried chives because I always keep some on hand for homemade ranch dressing (though fresh will work great too).

Salt and pepper – add this to taste.

Scroll down for full printable recipe.

Ingredients needed to make squash casserole shown here.

How to Make Squash Casserole:

  1. Heat oven, prepare baking dish: Preheat oven to 350 degrees. Spray a 13 by 9-inch baking dish with non-stick cooking spray.
  2. Parboil squash, drain: Bring a large pot of water to a boil. Add squash and let boil just until nearly tender, about 5 – 6 minutes. Drain into a colander, set aside to drain well.
  3. Make cheese mixture: Stir together sour cream, egg, 1/3 cup breadcrumbs, cheddar cheese, 1/2 cup parmesan cheese, parsley and chives. Set aside.
  4. Saute aromatics: Melt 1 Tbsp butter in a 12-inch saute pan or deep skillet over medium heat. Add onion and saute until tender, about 7 minutes. Add garlic and saute 1 minute longer. Remove from heat.
  5. Toss squash and cheese mixture: Add squash and sour cream mixture to pan (with onions) and season with salt and pepper to taste. Toss mixture and pour and spread into prepared baking dish.
  6. Bake: Cover with foil and bake in preheated oven 20 minutes.
  7. Make panko mixture, add to casserole: Melt remaining 2 Tbsp butter in a small mixing bowl. Toss in 3/4 cup panko and 1/2 cup parmesan cheese.
  8. Add topping and continue baking: Sprinkle topping over casserole, move oven rack to upper third of the oven and return casserole to oven. Bake 10 minutes longer or until cheese has melted and casserole is heated through. Broil just briefly for a golden brown topping.

Steps showing how to make squash casserole.

Can I Make it in Advance?

Yes it can be prepped a day ahead of time. To do so:

  • Prepare as directed and add to the baking dish (wait to add the topping).
  • When ready to bake remove from refrigerator and let rest 30 minutes before baking.
  • Bake as directed (while adding topping partway through).
  • Add add a little extra bake time as needed to fully heat through.

Possible Variations:

  • Use zucchini in place of squash.
  • Try a different cheese such as romano for parmesan or a sharper gruyere for cheddar.
  • Add extra cheese.
  • Sneak in a sliced tomato.
  • Substitute crushed ritz crackers for panko (add extra and no broiling necessary).
  • Try it with creme fraiche in place of sour cream.

Baked yellow Squash Casserole in a white ceramic baking dish.

Tips for the Best Squash Casserole:

  • Work to cut squash evenly so they all cook evenly.
  • Preferably use smaller squash, or if large is what you have on hand cut into halves or even quarters if extra large before slicing (otherwise they won’t layer as nicely into baking dish and they just aren’t bite size).
  • Parboil (pre-cook slightly before baking) so the squash comes out nice and tender in the end.
  • Use freshly shredded cheeses for best flavor and melting texture.
  • Don’t walk away when broiling to toast the crumb topping, it can go from golden brown and beautiful to black and burned in a matter of seconds.

Close up image of wooden spoon with scoop of squash casserole.

More Delicious Yellow Squash Recipes:

Yellow Squash Casserole

5 from 10 votes

Made with tender yellow squash, a cheesy, creamy coating and it's finished with crispy toasted panko bread crumbs. It's a delicious, homestyle side dish that's perfect for holidays. Plus it's a great way to use up the abundance of summertime squash.

Servings: 12
Prep Time 25 minutes
Cook Time 35 minutes
Total Time 1 hour

Ingredients

  • 4 lbs. yellow squash (preferably small to medium), sliced into rounds about 1/3-inch thick
  • 1 cup sour cream
  • 1 large egg
  • 3/4 cup + 1/3 cup panko breadcrumbs, divided
  • 1 1/4 cups shredded sharp cheddar cheese
  • 1/2 cup chopped parsley
  • 2 Tbsp dried chives
  • 3 Tbsp butter, divided
  • 1 medium yellow onion, chopped
  • 2 garlic cloves, minced (2 tsp)
  • 1 cup finely shredded parmesan cheese, divided
  • Salt and freshly ground black pepper

Instructions

  1. Preheat oven to 350 degrees. Spray a 13 by 9-inch baking dish with non-stick cooking spray.

  2. Bring a large pot of water to a boil. Add squash and let boil just until nearly tender, about 5 - 6 minutes. Drain into a colander, set aside to drain well.

  3. While squash is boiling in a mixing bowl stir together sour cream, egg, 1/3 cup breadcrumbs, cheddar cheese, 1/2 cup parmesan cheese, parsley and chives. Set aside.

  4. Melt 1 Tbsp butter in a 12-inch saute pan or deep skillet over medium heat. Add onion and saute until slightly golden brown and tender, about 7 minutes. Add garlic and saute 1 minute longer. Remove from heat.

  5. Add squash and sour cream mixture to pan (with onions) and season with salt and pepper to taste. Toss mixture to evenly coat the pour into prepared baking dish and spread even. Cover with foil and bake in preheated oven 20 minutes.

  6. Melt remaining 2 Tbsp butter in a small mixing bowl. Add in 3/4 cup panko and 1/2 cup parmesan cheese and toss to evenly coat mixture. Remove casserole from oven after the 20 minutes and sprinkle mixture evenly over top.

  7. Move oven rack to upper third of the oven, return casserole to oven. Bake 10 minutes longer or until cheese has melted and casserole is heated through.

  8. Turn on broiler and broil just briefly to make topping golden brown, about 1 - 2 minutes (don't walk away from it, it will brown quickly!). Serve casserole warm garnished with a little chopped parsley if desired.

Recipe Notes

POSSIBLE VARIATIONS:

  • Use zucchini in place of yellow squash.
  • Try a different cheese such as romano for parmesan or a sharper gruyere for cheddar.
  • Add extra cheese.
  • Sneak in a sliced tomato.
  • Substitute crushed ritz crackers for panko (use 35 crackers, and no broiling necessary).
  • Try it with creme fraiche in place of sour cream.
Nutrition Facts
Yellow Squash Casserole
Amount Per Serving
Calories 199 Calories from Fat 126
% Daily Value*
Fat 14g22%
Saturated Fat 8g50%
Cholesterol 53mg18%
Sodium 208mg9%
Potassium 486mg14%
Carbohydrates 11g4%
Fiber 2g8%
Sugar 5g6%
Protein 6g12%
Vitamin A 951IU19%
Vitamin C 30mg36%
Calcium 247mg25%
Iron 1mg6%
* Percent Daily Values are based on a 2000 calorie diet.
Course: Side Dish
Cuisine: American
Keyword: Squash Casserole
Author: Jaclyn

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30 Comments

  • KayKay

    Delicious! Nice, easy side. It’s a good basic recipe for any veg casserole … e.g., cauliflower, broccoli, carrots, etc. Thanks, Cooking Classy! P.S. recipe correction at point 5 : Add the sauteed onions into the sour cream mix, too! ;-)

    • Jaclyn

      Jaclyn Bell

      Sorry for any confusion, you’re adding the squash and sour cream to the onion mixture in the pan as pictured (I’ve added that in parenthesis to help make sense of it). So glad you enjoyed!

  • BDGT

    We absolutely loved this! I think where some people are getting lost with regards to the onion/garlic mixture is that after you have sauted them in Step 4 it doesn’t tell you when to add them to the squash. I immediately added mine to the squash after I removed them from the stove and gently mixed them in, before I proceeded with Step 5. I think it should also be noted that when you go to print the recipe, if you opt to change the serving size it doesn’t change the amounts you should add at different stages within the instructions. You will need to do that with the bread crumbs and Parmesan cheese as well as the size of the baking pan you use.

    • Jaclyn

      Jaclyn Bell

      Sorry for any confusion, you’re adding the squash and sour cream to the onion mixture in the pan as pictured (I’ve added that in parenthesis to help make sense of it). And thanks for pointing that out on serving size, it won’t automatically change any of those within any recipe it only adjust the amounts above to make calculation easier. Glad you liked it, thanks for your feedback!

  • Lin

    There does not seem to be enough sauce to cover squash. But I did not parboil the squash first so that may make a difference. Ha! I love the flavor and always love more ways to serve squash in the summer.

  • April A

    So easy and tastes amazing! I added a layer of yellow tomato slices FTW.

  • Betsy Ladday

    This is delicious. Takes some time with the prep work, but puts good use to an abundance of squash.

  • Richard

    This recipe requires a little work but it is outstanding! 5 stars!!

      • Tom Rocco

        Yes, we did that and removed from heat, but where do they go after that?

        • Jaclyn

          Jaclyn Bell

          From there you add the squash to the same pan. It may be helpful to refer to the step by step photos. Sorry for any confusion!

          • Tom Rocco

            Thanks. We just went by the written instructions. We enjoyed the recipe very much, used the leftovers in wraps for lunch!

          • Jaclyn

            Jaclyn Bell

            I’m so glad to hear you enjoyed the recipe Tom, thanks for letting me know! Leftovers sound tasty in wraps too.

  • Irene Merrill

    This is an excellent recipe. Unlike zucchini, yellow squash is very bland and needs some oomph. This does it. Will make this again…rather than give the squash away!