Yellow Squash Casserole Recipe

If you’re looking for a comforting dish that brings warmth to the dinner table, this Yellow Squash Casserole Recipe is exactly what you need. I absolutely love how this turns out — it’s creamy, cheesy, and has that perfect crispy topping that makes it irresistible. Whenever I’m craving something hearty yet fresh, this casserole never disappoints.

What makes this recipe special is how simple ingredients come together to create a dish that’s more than the sum of its parts. It’s a fantastic side for family dinners, potlucks, or holiday gatherings where you want to impress without hours in the kitchen. You’ll find that this Yellow Squash Casserole Recipe balances richness with a subtle kick from cayenne, giving it a unique twist you’ll want on repeat.

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Ingredients You’ll Need

I like how the blend of fresh squash with sharp cheddar and Parmesan cheeses creates a rich, flavorful base. These ingredients come together so well, and using crushed Ritz crackers gives it that nostalgic, crunchy finish.

• Unsalted butter: Use real butter for that creamy, luscious flavor and to help everything brown beautifully.
• Yellow squash: Fresh and thinly sliced into half-inch coins for even cooking and a nice texture.
• Yellow onion: Finely chopped to melt into the squash, adding sweetness and depth.
• Garlic cloves: Minced for a little punch that lifts the whole dish.
• Cayenne pepper: Just a touch to add warmth without overwhelming the flavors.
• Kosher salt: Essential for seasoning and bringing out the natural tastes.
• Freshly ground black pepper: For a touch of sharpness and spice.
• Large eggs: They bind the casserole nicely and add a custardy texture.
• Sour cream: Adds tang and creaminess that balances the cheddar.
• Mayonnaise: Helps keep it moist with a hint of richness and flavor.
• Shredded cheddar: Sharp cheddar goes best here — it melts perfectly and gives cheesy goodness.
• Parmesan cheese: Grated finely for a salty, savory depth of flavor.
• Ritz crackers: Crushed to create the crispy, buttery topping everyone raves about.

Variations

I like to mix things up depending on the season or what’s in my fridge, and this Yellow Squash Casserole Recipe is super versatile. Feel free to add your favorite extras or switch cheeses for a slightly different vibe.

• Adding fresh herbs: I’ve tossed in some chopped thyme or parsley — it brightens the casserole in a lovely way.
• Spicy kick: If you love heat, double the cayenne or even add some crushed red pepper flakes.
• Dairy swap: Use Greek yogurt in place of sour cream for a tangier version that’s just as creamy.
• Vegetable additions: Sometimes I throw in a handful of chopped bell peppers or fresh spinach for an extra veggie punch.
• Gluten-Free Topping: Swap the Ritz crackers for gluten-free breadcrumbs or crushed nuts for crunch.

How to Make Yellow Squash Casserole Recipe

Step 1: Prep the Oven and Dish

Start by positioning your oven rack in the center and preheat to 350°F (175°C). Lightly grease a 13” x 9” baking dish with cooking spray — this helps the casserole slide out easily after baking, plus it prevents sticking. I usually give it a quick spray and then a wipe with a tiny bit of butter for extra flavor.

Step 2: Cook the Squash and Onion

Heat 2 tablespoons of butter in a large skillet over medium heat, then add the sliced yellow squash and chopped onion. Cook, stirring often, until the squash softens and the onions become translucent, about 8 minutes. This step is where the veggies start getting tender and develop great flavor — just keep an eye so they don’t brown too much.

Step 3: Add Garlic, Seasonings, and Drain

Stir in the minced garlic and cayenne pepper, seasoning with salt and freshly ground black pepper to taste. I like to cook it just another minute to let those aromas bloom. Then, transfer the mixture to a colander set over a bowl and let it drain for 5 minutes to get rid of excess moisture — this step prevents your casserole from becoming watery.

Step 4: Mix the Casserole Filling

In a large bowl, whisk together the eggs, sour cream, and mayonnaise until smooth. Stir in the shredded cheddar and grated Parmesan, seasoning again with salt and pepper if needed. Gently fold in the drained squash and onion mixture to combine everything evenly without breaking the squash up too much. This creates that creamy, cheesy base everyone loves.

Step 5: Prepare the Crunchy Topping

Microwave the remaining 2 tablespoons of butter in a medium heatproof bowl until melted — about 20 seconds. Add the crushed Ritz crackers and toss to coat them in butter thoroughly. This step is the secret to that golden, irresistible crust on top.

Step 6: Assemble and Bake

Spread the squash mixture evenly in the prepared baking dish. Sprinkle the buttered cracker crumbs over the top, creating a beautiful, crunchy layer. Bake at 350°F for about 20 minutes, or until the casserole is bubbly and the cracker topping is golden brown. The smell at this point? Absolutely mouthwatering.

How to Serve Yellow Squash Casserole Recipe

Garnishes

I often sprinkle a little fresh chopped parsley or chives on top just before serving—it adds a pop of color and a fresh note against the cheesy richness. If I’m feeling extra indulgent, a light drizzle of hot sauce can be a fantastic finishing touch too.

Side Dishes

This Yellow Squash Casserole Recipe pairs wonderfully with grilled chicken, roasted pork, or even a simple green salad. For holiday dinners, I love serving it alongside mashed potatoes and a crisp vegetable like steamed green beans. It acts as the perfect cheesy complement.

Creative Ways to Present

For special occasions, I’ve used small ramekins to create individual portions—this not only makes it feel fancy but also ensures everyone gets a crispy top. Serving it in a vibrant, shallow casserole dish also brings a festive vibe to the table, especially when paired with colorful garnishes.

Make Ahead and Storage

Storing Leftovers

If you have any leftovers (and you might, but probably not!), pack them tightly in an airtight container and refrigerate. I’ve noticed the casserole keeps its flavor well for up to 3 days. Just keep the topping separate if possible to maintain crunch.

Freezing

This casserole freezes beautifully! Just assemble it in a freezer-safe dish without the cracker topping, then freeze. When you’re ready to bake, thaw overnight in the fridge, add the topping fresh, and bake as directed. I’ve done this multiple times, and it tastes just as good as fresh.

Reheating

To reheat, I pop it in a 350°F oven for about 15-20 minutes until warmed through and the topping is crisp again. Microwaving works in a pinch, but you’ll lose some crispness. I always prefer the oven method to keep that delightful crunch intact.

FAQs

Final Thoughts

This Yellow Squash Casserole Recipe is a true kitchen gem that’s become a favorite in my family. It’s easy to make, satisfying, and every bite feels like a cozy hug. I encourage you to try it out soon — whether it’s a weeknight dinner or a special occasion, this casserole will bring smiles and happy plates. Trust me, once you taste that luscious inside and crispy topping combo, it’ll become a regular on your menu too.

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