Squash Casserole With Sour Cream That Even Picky Eaters Crave

Forget the bland veggie side that gets ignored. This Squash Casserole With Sour Cream is the comfort-food flex that turns yellow squash into a golden, creamy, crunchy masterpiece. We’re talking silky interior, savory onions, tangy sour cream, and a buttery cracker crown that shatters like applause.

One pan, simple ingredients, restaurant-level payoff. If you need a crowd-pleaser that doesn’t require a culinary diploma, this is your move.

What Makes This Special

This casserole nails the balance: rich but not heavy, fresh but indulgent, and crispy on top with a soft, custardy center. The sour cream adds tang and body, binding the sautéed squash and onions into a luxe base without turning it soupy.

A quick hit of cheddar brings savoriness, while a buttery cracker topping adds crunch that actually stays crunchy. Bonus: it reheats like a pro and plays nicely with everything from roast chicken to BBQ.

Ingredients

• 6 cups yellow squash, sliced into 1/4-inch rounds (about 4–5 medium)
• 1 medium yellow onion, thinly sliced
• 2 tablespoons unsalted butter (plus more for topping)
• 1 tablespoon olive oil
• 1 teaspoon kosher salt, divided
• 1/2 teaspoon black pepper
• 1/2 teaspoon garlic powder (or 2 cloves garlic, minced)
• 1 cup sour cream (full-fat recommended)
• 1 cup shredded sharp cheddar cheese
• 2 large eggs, lightly beaten
• 1/3 cup grated Parmesan
• 1 cup crushed buttery crackers (e.g., Ritz), lightly packed
• 2 tablespoons melted butter (for the topping)
• Optional: 1/4 teaspoon smoked paprika or cayenne for heat
• Optional: 2 tablespoons chopped fresh chives or parsley, for garnish

Step-by-Step Instructions

1. Preheat and prep. Heat the oven to 350°F (175°C). Grease a 2-quart baking dish.Set a colander over a bowl for draining the squash later.
2. Sweat the squash. In a large skillet, warm the olive oil and 1 tablespoon of butter over medium heat. Add squash and onions with 1/2 teaspoon salt. Cook, stirring occasionally, until the squash releases moisture and softens, 8–10 minutes.You’re not browning; you’re reducing water.
3. Drain like you mean it. Transfer squash and onions to the colander. Let sit 5 minutes, then press gently with a spatula to release excess liquid. This step keeps the casserole from turning watery—don’t skip it.
4. Build the base. In a large bowl, whisk sour cream, eggs, garlic powder, remaining 1/2 teaspoon salt, pepper, Parmesan, and optional paprika/cayenne.Stir in cheddar.
5. Combine. Fold drained squash and onions into the sour cream mixture until coated. Taste and adjust seasoning if needed (yes, it’s safe—everything’s cooked except the eggs, so just a tiny taste).
6. Fill the dish. Spread the mixture evenly in the prepared baking dish. Dot the top with the remaining 1 tablespoon butter in tiny pieces for extra richness.
7. Topping time. In a small bowl, mix crushed crackers with melted butter until sandy and clumpy.Sprinkle evenly over the casserole.
8. Bake. Place on the center rack and bake 25–30 minutes, until bubbling at the edges and the cracker crust is golden brown.
9. Rest and serve. Let it stand 10 minutes. Garnish with chives or parsley. Serve warm and accept compliments graciously.

Keeping It Fresh

Store leftovers in an airtight container in the fridge for up to 4 days.

Reheat in a 350°F oven for 10–12 minutes to revive the crunch. Microwave works in a pinch, but the topping softens (still tasty, just less dramatic). To prep ahead, assemble without the cracker topping, cover, and chill up to 24 hours.

Add topping just before baking. You can also freeze the assembled, unbaked casserole (without topping) for up to 2 months; thaw overnight, add topping, and bake.

Health Benefits

• Squash brings fiber and vitamins. Yellow squash is rich in vitamin C, manganese, and antioxidants—helpful for immune support and cellular health.
• Protein from eggs and cheese. The eggs bind the casserole and add high-quality protein; cheddar contributes calcium for bone health.
• Portion control is painless. This is a veggie-forward comfort dish. Pair with lean protein and a salad for a balanced plate without feeling like you “dieted.”
• Customizable fats. Using full-fat sour cream improves satiety; if you prefer lighter, swap in reduced-fat versions (see Variations).IMO, flavor wins, but you do you.

Avoid These Mistakes

• Skipping the drain. If you don’t press out moisture from the squash, you’ll get a soggy center and a sad crust. Nobody wants casserole soup.
• Overcooking the squash during sauté. Mushy squash breaks down too much and releases water later. Aim for just-tender.
• Adding topping too early for make-ahead. It’ll absorb moisture in the fridge and lose its crunch.Add it right before baking.
• Under-seasoning. The dairy mellows flavors. Taste and adjust salt and pepper before it hits the oven.
• Using pre-shredded cheese only. Bagged cheese has anti-caking agents that can dull meltiness. Half fresh, half bagged is a good compromise if you’re busy.

Recipe Variations

• Lighter Touch: Use reduced-fat sour cream and part-skim cheddar.Add 1 extra egg to help set the lighter dairy.
• Herb Garden: Fold in 2 tablespoons chopped dill, basil, or thyme. Finish with lemon zest for brightness.
• Heat Lovers: Add minced jalapeño or 1/2 teaspoon red pepper flakes. Pepper jack cheese swaps in well.
• Gluten-Free: Use GF buttery crackers or crushed cornflakes.Verify your spices and cheeses are GF.
• Protein Boost: Stir in 1 cup cooked, crumbled bacon or diced rotisserie chicken. Yes, it’s dangerously good.
• Mushroom Umami: Sauté 8 ounces sliced cremini with the onions for a deeper, steakhouse vibe.
• Greek-ish: Swap sour cream for full-fat Greek yogurt, use feta + mozzarella, and add oregano and spinach.
• Panko Upgrade: Replace crackers with panko tossed in butter and a little Parmesan for extra crunch.

FAQ

Can I use zucchini instead of yellow squash?

Yes, but zucchini holds more water. Slice, salt lightly, let it sit 10 minutes, then pat dry before sautéing.

Still drain after cooking to avoid sogginess.

Is there a substitute for sour cream?

Full-fat Greek yogurt works well and adds tang. Crème fraîche is luxe and ultra-stable when baked. Just avoid thin, low-fat yogurts that can separate.

Do I have to use eggs?

Eggs help the casserole set.

For an egg-free version, use 2 tablespoons cornstarch whisked into the sour cream and add 1/4 cup milk; bake until firmly set. Texture will be slightly softer but still sliceable.

Can I make this ahead for a party?

Absolutely. Assemble the filling, cover, and refrigerate up to 24 hours.

Add the cracker topping right before baking. For serving, keep warm at 200°F and the crust will stay crisp for about 30–40 minutes.

Why is my topping not crunchy?

It likely absorbed moisture before baking or didn’t get enough fat. Toss crumbs with melted butter right before topping, and bake until golden.

Re-crisp by broiling 1–2 minutes (watch closely).

What size dish should I use?

A 2-quart baking dish or 8×8-inch pan works. For a thinner, crisper ratio, use a 9×13-inch pan and reduce bake time by 5 minutes.

Can I freeze leftovers?

Yes. Cool completely, wrap tightly, and freeze up to 2 months.

Reheat covered at 350°F until hot, then uncover for 5–7 minutes to refresh the crust.

My Take

This Squash Casserole With Sour Cream is the definition of low-effort, high-reward cooking. It’s cozy without being heavy, nostalgic without tasting dated, and sturdy enough to survive the fridge without losing its charm. The sour cream is the quiet hero—it turns everyday squash into something creamy, tangy, and borderline addictive.

FYI, I’m team extra cracker crust and a little smoked paprika; that combo makes it taste like you planned a whole menu when you actually didn’t. Serve it with grilled chicken or a big salad and call it a win.