I first made Squash Casserole on a random Tuesday with a pile of yellow squash from the farmers market and had no idea it would become the dish my family requests at every gathering. The sweet, mellow squash bakes up in a creamy egg custard, then gets finished with a buttery cracker crust that crackles when you scoop it. It comes together with simple pantry staples, so no last-minute grocery runs needed.

If you love cozy veggie sides, you might also enjoy Easy Eggplant Mozzarella Sandwiches recipe or Easy Texas Chili recipe , Easy Sausage and Kale Casserole recipe both are weeknight heroes just like this one.
Why YOU'll love This Squash Casserole
A few things make this Squash Casserole stand out:
- The egg and milk mixture creates a custard base that keeps everything moist and holds it together without feeling heavy.
- Sauteing the squash and onion first removes extra water, so you get a firm, scoopable Squash Casserole instead of a soggy one.
- Butter crackers mixed into the filling AND scattered on top give you flavor and crunch from the inside out.
Jump to:
Squash Casserole Ingredients
Simple, familiar ingredients - most of which you probably already have on hand.
See Recipe Card Below This Post For Ingredients Quantities
- Yellow Squash : The star of the dish. Yellow squash is naturally sweet and tender. Cutting them thin means they cook evenly and layer beautifully in the Squash Casserole .
- Yellow Onion: Adds a gentle savory depth. Cooking it low and slow lets it go sweet and slightly caramelized, which balances the mildness of the squash.
- Shredded Cheddar Cheese : Melts into the Squash Casserole and gives it that rich, cheesy pull. Sharp cheddar works great if you want a little more bite.
- Shredded Parmesan Cheese : Sprinkled on top before baking, Parmesan crisps up into a golden, salty crust that is honestly the best part of every scoop.
- Garlic : Stirred in at the end of the saute so it blooms without burning. It adds a warm, savory backbone to the whole dish.
- Salted Butter : Used to soften the onions and squash in the pan. Butter carries flavor and adds richness throughout.
- Salt : Added in two stages - once when cooking the onion, and again in the egg mixture to season the filling throughout.
- Eggs : The binder that holds the Squash Casserole together. They create a light custard with the milk that keeps the texture creamy, not dry.
- Milk: Works with the eggs to create a pourable custard base. Whole milk gives the richest result, but 2% works just fine.
- Fresh Parsley : Adds a little color and a fresh herby note to the egg mixture. Subtle but makes a difference.
- Black Pepper : Freshly cracked pepper adds warm heat and keeps the Squash Casserole from tasting flat.
- Crushed Red Pepper : Just a whisper of heat that you won't notice consciously - but you'd miss it if it weren't there.
- Butter Crackers : Half goes into the filling for texture from within, half goes on top for that signature golden crunch. Classic and perfect.
How to Make Squash Casserole
Preheat the oven: Set your oven to 350 degrees F (175 degrees C). This gives the oven plenty of time to fully heat while you prep the veggies.
Prepare your ingredients: Slice the yellow squash into ¼ inch discs, julienne the onion, shred the cheddar and Parmesan, and mince the garlic. Getting everything prepped before you start cooking makes the whole process smooth.
Saute the onion: In a large skillet, melt the butter over medium heat. Add the sliced onion and ¼ teaspoon of salt. Cook for about 6 minutes, stirring occasionally, until the onion is tender and just starting to caramelize at the edges.
Add the squash: Toss the squash discs into the skillet with the onion. Cook for about 5 minutes, stirring gently, until the squash is al dente - tender but still holding its shape. You don't want mush here.
Add the garlic: Stir in the minced garlic and cook for 2 more minutes. You'll smell it immediately. Don't walk away at this stage.

Transfer to the casserole dish: Scoop the cooked vegetables into a 3-quart Squash Casserole dish and spread them out evenly.
Make the egg mixture: In a separate bowl, beat the 2 eggs with the milk, fresh parsley, remaining ¾ teaspoon salt, black pepper, and crushed red pepper. Whisk until combined.
Combine with the squash: Pour the egg mixture over the squash in the Squash Casserole dish. Stir gently to coat everything evenly.

Add crackers and cheddar to the filling: Mix half of the crushed crackers with the shredded cheddar. Stir this mixture directly into the Squash Casserole . This gives you flavor and crunch throughout the whole dish.
Top the casserole: Scatter the remaining crushed crackers evenly over the top, then sprinkle on the shredded Parmesan. This is what will brown into that gorgeous golden crust.
Bake: Slide the dish into the oven and bake for 45 minutes, until the top is deep golden brown and the Squash Casserole is bubbling at the edges. Your kitchen is going to smell incredible.
Cool slightly before serving: Let the Squash Casserole rest for 5 to 10 minutes before scooping. This helps it set so you get clean, scoopable servings rather than a runny mess.
Substitutions and Easy Swaps
- No yellow squash? Zucchini works beautifully here. You can also do half zucchini and half yellow squash for a nice mix.
- Dairy-free? Use plant-based butter and swap the milk for unsweetened oat milk. Vegan shredded cheese melts differently but still gives you a great result.
- No butter crackers? Ritz are the classic choice, but any round buttery cracker works. Crushed saltines also do the job - just reduce added salt slightly.
- Want more protein? Stir in a cup of diced cooked chicken or crumbled cooked sausage with the squash before adding the egg mixture.
Equipment for Squash Casserole
- Large skillet
- 3-quart casserole dish
- Mixing bowls
- Oven
Storing and Reheating Leftovers
Fridge: Cover the Squash Casserole dish tightly or transfer leftovers to an airtight container. It keeps well for up to 4 days. Reheat individual portions in the microwave for 1 to 2 minutes, or warm the whole dish in a 325 degree oven until heated through.
Freezer: Let it cool completely, then cover tightly with plastic wrap and foil. Freeze for up to 2 months. Thaw overnight in the fridge before reheating. Note that squash will soften slightly after freezing.
Expert Tips
Don't skip the saute step: Cooking the squash on the stovetop first removes excess moisture. If you add raw squash, the Squash Casserole will be watery.
Al dente is the goal: You want the squash slightly firm when it goes into the Squash Casserole dish. It keeps cooking in the oven, so pull it off the heat while it still has a little bite.
Crush the crackers into varied sizes: A mix of fine crumbs and small chunks gives you better texture - the crumbs absorb into the filling while the chunks stay crunchy on top.
Rest before serving: Even 5 minutes of resting after baking makes a big difference. The custard sets and you'll get much cleaner scoops.
FAQ
How do you make squash casserole creamy?
The egg and milk mixture is the key. It creates a custard that coats every piece of squash and cheese as it bakes. Sauteing the vegetables first also helps - less moisture means a thicker, creamier result rather than a thin, watery one.
What is the best type of squash for casserole?
Yellow summer squash is the classic choice and what this recipe is built around. It's mild, slightly sweet, and bakes up beautifully. Zucchini is a close second and works as a one-for-one swap.
Can you use zucchini in squash casserole?
Absolutely. Zucchini works just as well as yellow squash here. The flavor is a little more neutral, but the texture and cooking time are almost identical. A 50/50 mix of both is a great option too.
Can you freeze squash casserole for later?
Yes. Let it cool completely, then cover tightly with plastic wrap and foil. It freezes for up to 2 months. The squash will be a bit softer after thawing, but the flavor stays great. Thaw overnight in the fridge and reheat covered in the oven at 325 degrees.
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Pairing
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Squash Casserole
Ingredients
Method
- Preheat the oven to 350°F (175°C). Gather all the ingredients: yellow squash, onion, cheeses, garlic, and crackers. prep
- In a large skillet, melt the salted butter over medium heat. Add the yellow onion and ¼ teaspoon salt. Sauté for about 6 minutes, until the onion becomes tender and begins to caramelize. prep
- Add the sliced yellow squash to the skillet and cook for about 5 minutes, until tender but still al dente. prep
- Add the minced garlic to the skillet and cook for another 2 minutes, until fragrant. prep
- Transfer the cooked onion and squash mixture to a 3-quart casserole dish. assemble
- In a separate bowl, beat the eggs and add milk, fresh parsley, remaining salt, black pepper, and crushed red pepper flakes. Pour this egg mixture over the squash in the casserole dish. mix
- In a bowl, combine half of the crushed crackers with the shredded cheddar cheese. Stir to combine, then add this mixture to the casserole dish with the squash. mix
- Top the casserole with the remaining crushed crackers and sprinkle with Parmesan cheese. assemble
- Bake the casserole in the preheated oven for 45 minutes, or until the top is golden and bubbly. bake













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