Cheesy yellow squash casserole layers tender squash and sweet onion in a creamy cheddar filling under a buttery cracker crumb topping.
It is a reliable side for family dinners and potlucks. Cook the squash until soft and drain it well before mixing, since extra liquid is the usual cause of a loose casserole. A colander and a wooden spoon make this quick.
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Why This Cheesy Yellow Squash Casserole Recipe Works
Cooking the squash and onion first softens them and releases moisture, which you drain away so the casserole sets instead of turning soupy. Squash is mostly water, so this step matters more than any other.
Sour cream, an egg, and cheddar combine into a creamy binder, and garlic powder adds savory depth. The mixture should be thick enough to hold a spoon upright.
Buttery crumbs on top bake into a golden crust that gives crunch against the soft filling. Melted butter helps the crumbs brown evenly.
Ingredients for Cheesy Yellow Squash Casserole
- Filling: yellow squash, onion, egg, cheddar cheese, sour cream, garlic powder, and pepper.
- Topping: crushed round buttery crackers and melted butter.
Yellow squash. Zucchini can replace some or all of the squash, and either one should be sliced into even coins. Small, firm squash have fewer seeds and a milder flavor.
Onion. Yellow or white onion both soften and sweeten as they cook with the squash. Dice the onion small so it softens in the same time.
Cheddar. Sharp cheddar gives more flavor, and Monterey Jack makes a milder casserole. Use a mix of both for a balanced flavor.
Sour cream. It adds creaminess and tang. Greek yogurt works but tastes slightly tangier.
Cracker topping. Round buttery crackers give a rich crunch, and crushed cornflakes or gluten free crackers suit guests who avoid wheat.
How to Make Cheesy Yellow Squash Casserole
1. Heat the oven. Heat the oven to 350 degrees F and butter a baking dish.
2. Prep the vegetables. Slice the squash into coins and dice the onion. Aim for coins about a quarter inch thick.
3. Cook them down. Saute the squash and onion in a skillet with a tablespoon of the butter until tender. Stir often so nothing browns too much.
4. Drain and mash. Drain well in a colander, pressing out the liquid, and mash the squash lightly. Leave a few small chunks for texture.
5. Mix the filling. Stir in the egg, cheddar, sour cream, half the crushed crackers, garlic powder, and pepper.
6. Add the topping. Spread the mixture in the dish, cover with the remaining crumbs, and drizzle with the rest of the melted butter.
7. Bake. Bake about thirty minutes, until golden and bubbly and the center reaches 165 F.
How to Serve Cheesy Yellow Squash Casserole
Serve this casserole hot alongside juicy cheeseburgers or roast chicken. Soft buttery rolls, bacon green beans, and baked beans fill out a Southern style plate.
How to Store and Reheat Cheesy Yellow Squash Casserole
Cool leftovers and refrigerate within two hours in a covered dish. They keep for up to three days. You can freeze the casserole unbaked for a couple of months, though the texture may soften a little. Reheat until the center reaches 165 F.
Tips and Variations for Cheesy Yellow Squash Casserole
Flag the allergens. This casserole contains milk, egg, and wheat, and some crackers also contain soy.
Do not taste the raw filling. The mixture contains raw egg, so wash your hands and utensils after mixing. Keep the bowl away from ready to eat foods.
Drain thoroughly. Press the cooked squash in a colander until the liquid stops dripping. A clean kitchen towel can absorb any last moisture.
Check doneness. The casserole is done when the center reaches 165 F and the top is bubbly.
Shred your own cheese. Block cheese melts more smoothly than pre shredded bags.
Add a little heat. A pinch of cayenne or diced jalapeno adds a gentle kick.
Make ahead. Assemble the casserole, cover, and refrigerate until baking, adding a few extra minutes in the oven. Check that the center is hot before serving.
Check trusted guidance. For storage basics, read the Purdue Extension guide to storing leftovers.
Frequently Asked Questions About Cheesy Yellow Squash Casserole
Can I make cheesy yellow squash casserole ahead of time?
Yes. Assemble it, cover it, and refrigerate until baking, or freeze it unbaked. Add a few extra minutes of bake time if it goes in cold.
Why is my cheesy yellow squash casserole watery?
The squash was not drained well enough. Press out the liquid after cooking before mixing.
Can I use zucchini in cheesy yellow squash casserole?
Yes. Zucchini works in place of some or all of the squash and tastes like summer.
What can I use instead of crackers?
Crushed cornflakes or gluten free crackers work well for the topping. Toss them with a little melted butter first.
Can I use Greek yogurt?
Yes, in place of sour cream, though the casserole will taste a little tangier. Use the same amount.
Cheesy Yellow Squash Casserole
Equipment
- Large skillet
- Colander
- Baking dish
Ingredients
Main Ingredients
- 6 medium yellow squash about 2 pounds, sliced into coins
- 1 medium onion diced
- 1 large egg beaten
- 2 cup shredded cheddar cheese sharp cheddar for more flavor
- 1 cup sour cream Greek yogurt can be used
- 1 cup crushed round buttery crackers divided, half in the filling and half on top
- 3 tbsp unsalted butter melted, divided for the skillet and the topping
- ¼ tsp black pepper
- 1 tsp garlic powder optional
Instructions
Cooking
- Cook. Heat the oven to 350 degrees F. Saute the squash and onion in 1 tablespoon of the butter until tender.
- Drain. Drain well in a colander and mash lightly.
- Mix. Stir in the egg, cheddar, sour cream, half the crushed crackers, garlic powder, and pepper.
- Top. Spread in a buttered baking dish, add the remaining crackers, and drizzle with the rest of the butter.
- Bake. Bake about 30 minutes until golden, bubbly, and 165 F in the center.
