Instant Pot Squash Casserole

Nothing says home more than my homemade Instant Pot Squash Casserole! If you’re looking for a delicious meal, get some vegetables and cook them in an Instant Pot to avoid extra oil. But, what to do to add some taste and flavor to the vegetables? This is where my Instant Pot squash casserole recipe comes to the rescue!

If you grew up anywhere around Southern potlucks, church dinners, or holiday tables, there’s a pretty good chance squash casserole showed up at least a few times a year. Creamy squash, buttery crackers, melty cheese, and that cozy baked casserole texture somehow turn simple yellow squash into something people actually get excited about eating.

This Instant Pot squash casserole takes all those classic Southern-style flavors and makes the process easier and faster without losing the cozy homemade feel. The pressure cooker softens the squash quickly while still giving you that creamy casserole texture everybody expects.

Why You'll Love This Instant Pot Squash Casserole Recipe

But that’s just the base of the casserole. The topping is another story altogether! The buttery, salty, and toasty Ritz crackers, mixed with cheese, spread on top of the casserole, and baked to crispy perfection are simply heavenly!

The best part? You can make this healthy instant pot squash casserole in under 20 minutes!

So, what are you waiting for? Slice those squash into wheels, saute the Vidalia onions, throw in some soup and cheese, and you have yourself a warm and satisfying bowl of delectable casserole!

The Ingredient Breakdown

How to Make Instant Pot Squash Casserole (Step-by-Step)

Step 1: Sauté the Onion

Press the Sauté button on your Instant Pot and make sure the liner is in place. Add the tablespoon of olive oil and let it heat until the pot reads Hot. Add your diced Vidalia onion and cook for three to four minutes, stirring occasionally, until the onion has softened and turned slightly translucent. You are not trying to caramelize it, just take the raw edge off. The sweetness of the onion will bloom beautifully once everything pressure cooks together.

Step 2: Deglaze and Add the Squash

Pour in the quarter cup of water and use a wooden spoon or spatula to scrape up any bits stuck to the bottom of the pot. This prevents the burn notice and adds flavor to the cooking liquid. Press Cancel to turn off the Sauté function. Add your sliced yellow squash wheels directly to the pot over the onion. Season with the cracked black pepper and a pinch of sea salt, then stir everything together so the squash is evenly coated. The pot will look very full at this stage and that is completely normal. Squash compresses dramatically under pressure.

Step 3: Pressure Cook on High for 10 Minutes

Place the lid on the Instant Pot, lock it into the sealed position, and make sure the steam vent is set to Sealing. Select Pressure Cook or Manual on High pressure and set the timer for 10 minutes. The pot will take a few minutes to come to pressure. While it does, preheat your oven to 425 degrees F and prep your baking dish with non-stick spray.

Step 4: Quick Release and Drain — This Step Is Critical

When the cook time is up, do a quick pressure release by carefully turning the steam vent to the Venting position. Once the float valve drops and it is safe to open, remove the lid. Here is where so many squash casseroles go wrong: you must drain the liquid from the pot thoroughly before adding anything else. Use a colander or a fine mesh strainer and press the squash gently to remove as much liquid as possible. Skipping this step means a watery, soupy casserole instead of a creamy, cohesive one.

Step 5: Stir in the Soup and Cheese

Return the well-drained squash and onion mixture to the Instant Pot or transfer to a large mixing bowl. Add the entire can of cream of mushroom soup and half a cup of the shredded cheddar cheese. Stir everything together gently until well combined. Taste the mixture now and adjust for salt and pepper. The filling should taste creamy, savory, and well-seasoned before it ever goes into the baking dish.

Step 6: Assemble and Bake

Transfer the squash mixture into your prepared casserole dish and spread it into an even layer. Sprinkle the remaining half cup of shredded cheddar cheese evenly over the top. Follow that with a generous, even layer of crushed Ritz crackers. Place the casserole dish in the preheated 425 degree oven and bake for four to five minutes, just until the cracker topping turns a beautiful golden brown and the cheese underneath is bubbling. Watch it closely because it can go from golden to burnt very quickly. Remove from the oven and let it sit for a few minutes before serving.

Pro Tips for the Best Squash Casserole

Make it ahead and refrigerate before baking. Assemble through the topping step, cover tightly, and refrigerate overnight. Add five to seven extra minutes of oven time the next day since it will be going in cold. Perfect for holiday prep.

Drain thoroughly and do not skip it. Yellow squash releases a tremendous amount of water under pressure. Drain it well and even press it gently with a paper towel if needed. A properly drained casserole is creamy. An under-drained one is watery.

Slice the squash thin and uniform. About 1/8 of an inch is the sweet spot. Too thick and some pieces will still have texture when the rest is done. A mandoline makes this fast and precise.

Use freshly shredded cheese. After years working in restaurant kitchens, I always grate my own cheese for dishes like this. Pre-shredded cheese has coatings that prevent smooth melting. Two extra minutes of grating makes a noticeably better casserole.

Add butter to the cracker topping for extra richness. Crush your Ritz crackers and toss them with one tablespoon of melted butter before spreading over the casserole. It makes the topping even more golden, rich, and irresistible.

This recipe doubles perfectly. Use a 9×13 baking dish and double all the ingredients. An 8-quart Instant Pot handles a double batch; a 6-quart may need two rounds for the squash.

This Instant Pot squash casserole is one of those recipes I come back to again and again because it just works every single time. Creamy, cheesy, with that irresistible golden cracker crust on top. It is cozy comfort food at its Southern best, and the Instant Pot makes it faster and more foolproof than the traditional oven method. That is my favorite kind of recipe.

If you make this, please come back and leave a comment below. Did you bring it to a holiday dinner? Did you add jalapeño or try a different cheese? Did the cracker topping get devoured before you could even get a photo? Tell me everything. And if you tag me on social media, I want to see your casserole dish. Happy cooking, everyone.

More Easy Instant Pot Recipes To Enjoy

• Instant Pot Oreo Cheesecake
• Air Fryer Sesame Chicken
• Air Fryer Kung Pao Chicken
• Instant Pot Thai Chicken Thighs
• Instant Pot Butter Potatoes
• Instant Pot Butter Chicken
• Sweet Potato Pie Bars

FAQs: Squash Casserole, Sorted

Can I make this instant pot squash casserole ahead of time?

Yes, and it is actually one of the best casseroles to prep in advance. Cook the squash in the Instant Pot, drain it thoroughly, mix in the soup and cheese, and transfer everything to the casserole dish. Top with cheese and crackers, cover tightly with foil, and refrigerate for up to one day. When you are ready to serve, bake uncovered at 425 degrees F for eight to ten minutes until golden and bubbly. No stress on the day.

Why is my squash casserole watery?

Almost always because the squash was not drained well enough after pressure cooking. Yellow squash releases a tremendous amount of liquid under pressure. After the quick release, transfer the squash to a colander and press it gently to remove as much water as possible before mixing in the soup and cheese. If your casserole is already in the dish and looking watery, bake it a few extra minutes to allow some of the liquid to evaporate.

Can I use zucchini instead of yellow squash?

Absolutely. Zucchini and yellow squash are very similar in flavor and texture and can be swapped one for one in this recipe. Using a mix of both gives you a more colorful, visually interesting casserole. Green and yellow together looks gorgeous in the baking dish and tastes every bit as good.

Do I need exactly 1/4 cup of liquid for the Instant Pot to work?

The quarter cup of water is just enough for the Instant Pot to create the steam it needs to reach pressure since the squash releases significant liquid of its own during cooking. If you want a little more insurance or you are using a larger Instant Pot, adding up to half a cup of water or broth is perfectly fine. Just make sure you drain well afterward.

Can I swap the Ritz crackers for something else?

Yes. Panko breadcrumbs tossed in a tablespoon of melted butter give you a lighter, crispier crust that is equally delicious. Crushed potato chips add an extra salty crunch. Crushed butter crackers of any brand work fine. The key is getting an even layer of something crunchy and buttery on top so it crisps up beautifully under the broiler or in the oven.

Is this squash casserole vegetarian?

Yes, the base recipe as written is completely vegetarian. Just make sure your cream of mushroom soup is made without chicken broth, as some canned varieties do contain it. There are several vegetarian versions of cream of mushroom soup readily available at most grocery stores.

Can I make this in a 6-quart Instant Pot?

Yes. The recipe as written fits comfortably in a 6-quart Instant Pot. Six medium yellow squash compressed under pressure is no problem for a 6-quart. If you plan to double the recipe for a crowd, cook the squash in two batches to stay safely below the max fill line, then combine everything in the mixing step before transferring to a 9×13 baking dish.