Easy Yellow Squash Casserole with Stuffing

Here is my favorite yellow squash casserole recipe, with tender squash, savory cream of mushroom soup, sour cream, herb stuffing mix, and plenty of melted sharp cheddar cheese.

This casserole is a real crowd-pleaser at potlucks and family dinners. I love how the stuffing gets crispy on top while everything underneath stays creamy and comforting. It’s the kind of dish that disappears fast, so you might want to make two!

What Kind of Yellow Squash Should I Use?

Any yellow squash you find at the grocery store will work great for this casserole, whether it’s straightneck or crookneck varieties. Look for squash that feels firm to the touch and has smooth, unblemished skin – avoid any that feel soft or have dark spots. Medium-sized squash (about 6-8 inches long) tend to have the best flavor and texture, as the really large ones can sometimes be watery or have tougher seeds. If you can’t find yellow squash or just want to switch things up, zucchini makes an excellent substitute and cooks exactly the same way.

Options for Substitutions

This casserole is really forgiving when it comes to swapping ingredients:

• Yellow squash: Zucchini works perfectly as a swap – they cook the same way and have a similar texture. You can also mix both yellow squash and zucchini for some variety.
• Cream of mushroom soup: If you’re not a mushroom fan, cream of chicken or cream of celery soup work just as well. You can also make a quick homemade version by mixing 1 cup of milk with 3 tablespoons of flour and some sautéed mushrooms.
• Sour cream: Greek yogurt is a great substitute here and adds a nice tang. Plain yogurt works too, though it’s a bit thinner.
• Stuffing mix: Don’t skip the stuffing – it’s what makes this casserole special. But if you need to, crushed Ritz crackers mixed with melted butter can work in a pinch, though the texture will be different.
• Hatch green chile: Can’t find hatch chiles? Use canned green chiles, poblano peppers, or even jalapeños if you want more heat. Just adjust the amount based on your spice preference.
• Cheddar cheese: Monterey Jack, Colby, or a Mexican cheese blend all melt nicely and taste great in this dish.

Watch Out for These Mistakes While Baking

The biggest mistake people make with squash casserole is not cooking off enough moisture from the squash before mixing it with the other ingredients, which leads to a watery, runny casserole – make sure to let that water evaporate during the stovetop cooking step and even consider draining any excess liquid before combining everything.

Another common error is skipping the initial sauté of the onions and squash, as this step not only removes moisture but also develops flavor and prevents the vegetables from releasing too much liquid while baking.

To avoid a dry casserole, don’t overbake it – pull it from the oven as soon as the cheese is melted and bubbly, since the residual heat will continue cooking it while it rests.

For extra flavor, try adding the cheese in two stages: mix half into the casserole before baking and sprinkle the rest on top, which gives you both a creamy interior and a golden, crispy cheese crust.

What to Serve With Yellow Squash Casserole?

This casserole is pretty hearty on its own, so I like to keep the sides simple and let it be the star of the plate. A basic protein like grilled chicken, pork chops, or even a simple roasted turkey breast pairs really well since the casserole already has so much flavor going on. If you want to add some freshness to balance out the richness, a crisp green salad with a light vinaigrette or some roasted green beans work great. For a full Southern-style spread, you could also serve it alongside cornbread and some sliced tomatoes with a sprinkle of salt and pepper.

Storage Instructions

Store: Keep any leftover casserole covered tightly with foil or in an airtight container in the fridge for up to 4 days. The stuffing topping might soften a bit as it sits, but it still tastes great. I actually think the flavors meld together even better the next day!

Freeze: This casserole freezes really well for up to 3 months. You can freeze it either before or after baking – just wrap it tightly in plastic wrap and then foil. If freezing unbaked, add about 15 extra minutes to the baking time when you’re ready to cook it from frozen.

Reheat: Warm up individual portions in the microwave for about 2 minutes, or reheat the whole dish covered with foil in a 350°F oven for 20-25 minutes until heated through. If you want to crisp up that stuffing topping again, just remove the foil for the last 5 minutes of reheating.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1500-1700
• Protein: 35-45 g
• Fat: 90-105 g
• Carbohydrates: 135-150 g

Ingredients

For the squash base:

• 2 tbsp unsalted butter
• 1 small onion, finely diced
• 3 medium yellow squash (sliced into 1/4-inch thick rounds)
• 1/2 cup water

For the assembly:

• 1 can (10.5 oz) condensed cream of mushroom soup
• 3/4 cup sour cream
• 6 oz herb seasoned stuffing mix
• 2 mild green chiles (seeds removed and finely diced)
• 1 1/2 cups sharp cheddar cheese, shredded
• 1/2 tsp garlic powder
• 1/4 tsp ground black pepper

Step 1: Prepare the Oven and Mise en Place

• 1 small onion, finely diced
• 3 medium yellow squash, sliced into 1/4-inch thick rounds
• 2 mild green chiles, seeds removed and finely diced
• 1 1/2 cups sharp cheddar cheese, shredded

Preheat your oven to 350°F and lightly grease a 9×13 inch baking dish.

While the oven heats, dice the onion finely, slice the yellow squash into 1/4-inch thick rounds, remove seeds from the green chiles and dice them finely, and shred the cheddar cheese.

Having everything prepped and ready will make the cooking process smooth and efficient.

Step 2: Sauté the Aromatics and Squash

• 2 tbsp unsalted butter
• 1 small onion, finely diced
• 3 medium yellow squash, sliced into 1/4-inch thick rounds
• 1/2 cup water

Melt the butter in a large skillet over medium heat and add the diced onion, cooking for about 2 minutes until it begins to soften and become fragrant.

Add the sliced squash and cook for another 2 minutes, stirring occasionally to coat the squash with the butter and allow it to start releasing its moisture.

Pour in the 1/2 cup of water and continue cooking for 5 minutes until the squash begins to soften but still has some texture—this partial cooking prevents the final casserole from becoming mushy.

Step 3: Build the Creamy Sauce Base

• 1 can condensed cream of mushroom soup
• 3/4 cup sour cream
• 2 mild green chiles, seeds removed and finely diced
• 1/2 tsp garlic powder
• 1/4 tsp ground black pepper

In a large mixing bowl, combine the cream of mushroom soup, sour cream, diced green chiles, garlic powder, and black pepper, stirring until well blended and smooth.

I like to whisk this mixture thoroughly to ensure the sour cream is fully incorporated and there are no lumps—this creates a silky sauce that coats the squash evenly.

Don’t add the stuffing mix yet; we’ll incorporate it in the next step.

Step 4: Combine Sauce with Squash and Stuffing

• Creamy sauce base from Step 3
• Partially cooked squash mixture from Step 2
• 6 oz herb seasoned stuffing mix

Add the partially cooked squash mixture from Step 2 to the creamy sauce base from Step 3, stirring gently to distribute the squash evenly.

Now fold in the herb seasoned stuffing mix until just combined—I recommend being gentle here so the stuffing pieces retain some texture rather than breaking down into mush.

The stuffing will absorb some of the sauce as the casserole bakes, so don’t worry if it seems a bit loose at this stage.

Step 5: Assemble and Bake the Casserole

• Squash and stuffing mixture from Step 4
• 1 1/2 cups sharp cheddar cheese, shredded

Pour the entire squash mixture into your prepared baking dish, spreading it evenly.

Sprinkle the shredded cheddar cheese generously over the top, covering as much surface area as possible for a nice golden, melty top.

Bake in the preheated 350°F oven for 25-30 minutes until the cheese is melted and golden and the casserole is heated through—you should see it bubbling slightly around the edges.

Step 6: Rest and Serve

Remove the casserole from the oven and let it rest for 2-3 minutes before serving.

This brief rest allows the sauce to set slightly, making it easier to scoop and serve without the casserole falling apart on the plate.

Easy Yellow Squash Casserole with Stuffing

Delicious Easy Yellow Squash Casserole with Stuffing recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings: 8 servings

Calories: 1600

Ingredients Method

Ingredients

  

For the squash base:

• 2 tbsp unsalted butter
• 1 small onion, finely diced
• 3 medium yellow squash (sliced into 1/4-inch thick rounds)
• 1/2 cup water

For the assembly:

• 1 can (10.5 oz) condensed cream of mushroom soup
• 3/4 cup sour cream
• 6 oz herb seasoned stuffing mix
• 2 mild green chiles (seeds removed and finely diced)
• 1 1/2 cups sharp cheddar cheese, shredded
• 1/2 tsp garlic powder
• 1/4 tsp ground black pepper

Method

 

1. Preheat your oven to 350°F and lightly grease a 9x13 inch baking dish. While the oven heats, dice the onion finely, slice the yellow squash into 1/4-inch thick rounds, remove seeds from the green chiles and dice them finely, and shred the cheddar cheese. Having everything prepped and ready will make the cooking process smooth and efficient.
2. Melt the butter in a large skillet over medium heat and add the diced onion, cooking for about 2 minutes until it begins to soften and become fragrant. Add the sliced squash and cook for another 2 minutes, stirring occasionally to coat the squash with the butter and allow it to start releasing its moisture. Pour in the 1/2 cup of water and continue cooking for 5 minutes until the squash begins to soften but still has some texture—this partial cooking prevents the final casserole from becoming mushy.
3. In a large mixing bowl, combine the cream of mushroom soup, sour cream, diced green chiles, garlic powder, and black pepper, stirring until well blended and smooth. I like to whisk this mixture thoroughly to ensure the sour cream is fully incorporated and there are no lumps—this creates a silky sauce that coats the squash evenly. Don't add the stuffing mix yet; we'll incorporate it in the next step.
4. Add the partially cooked squash mixture from Step 2 to the creamy sauce base from Step 3, stirring gently to distribute the squash evenly. Now fold in the herb seasoned stuffing mix until just combined—I recommend being gentle here so the stuffing pieces retain some texture rather than breaking down into mush. The stuffing will absorb some of the sauce as the casserole bakes, so don't worry if it seems a bit loose at this stage.
5. Pour the entire squash mixture into your prepared baking dish, spreading it evenly. Sprinkle the shredded cheddar cheese generously over the top, covering as much surface area as possible for a nice golden, melty top. Bake in the preheated 350°F oven for 25-30 minutes until the cheese is melted and golden and the casserole is heated through—you should see it bubbling slightly around the edges.
6. Remove the casserole from the oven and let it rest for 2-3 minutes before serving. This brief rest allows the sauce to set slightly, making it easier to scoop and serve without the casserole falling apart on the plate.