Cheesy Baked Summer Squash Casserole That Disappears Before Morning
Some dishes have a way of making you forget all about portion control, and this golden, bubbling summer squash casserole is absolutely one of them. With a gloriously cheesy top that browns to perfection in the oven and a creamy, tender interior packed with fresh squash, it is the kind of comfort food that brings everyone back for seconds — and thirds. It is easy enough for a weeknight but impressive enough to bring to any gathering, and fair warning: do not expect leftovers to survive until the next day.
Whether you grow summer squash in your garden or just pick some up at the farmers market, this casserole is one of the best ways to use it. The squash becomes melt-in-your-mouth soft while the cheese on top turns irresistibly golden and bubbly. This is pure, home-cooked goodness at its finest.
Ingredients
- 4 to 5 medium yellow summer squash, sliced into rounds
- 1 medium onion, finely diced
- 2 tablespoons butter
- 1 cup sour cream
- 1 can (10.5 oz) cream of chicken soup (or cream of mushroom for a vegetarian version)
- 1 cup shredded sharp cheddar cheese, divided
- 1 cup shredded mozzarella cheese, divided
- 2 eggs, lightly beaten
- Salt and black pepper to taste
- 1/2 teaspoon garlic powder
- Optional: 1 sleeve buttery crackers or seasoned breadcrumbs for topping
Method
- Preheat your oven to 350°F (175°C) and lightly grease a large baking dish or disposable aluminum pan.
- In a large skillet over medium heat, melt the butter and sauté the diced onion until soft and translucent, about 5 minutes. Add the sliced squash and cook for another 5 to 7 minutes until just tender. Season with salt, pepper, and garlic powder. Drain off any excess liquid — this step is important so your casserole does not turn watery.
- In a large mixing bowl, stir together the sour cream, cream of chicken soup, beaten eggs, and about three-quarters of both cheeses. Mix until well combined.
- Fold the cooked squash and onion mixture into the creamy cheese base until everything is evenly coated.
- Pour the mixture into your prepared baking dish and spread it out into an even layer.
- Sprinkle the remaining shredded cheddar and mozzarella generously over the top. If using crackers or breadcrumbs, crush them and scatter over the cheese layer for extra texture.
- Bake uncovered for 35 to 45 minutes, until the top is deeply golden and the casserole is set and bubbling around the edges.
- Let it rest for 5 to 10 minutes before serving — if you can wait that long.
Tips for the Best Casserole
Always drain your cooked squash well before mixing. Summer squash holds a surprising amount of water, and releasing that moisture before baking keeps the casserole rich and creamy rather than soupy. You can even press it gently with paper towels for best results.
For an extra layer of flavor, try mixing in a handful of freshly grated Parmesan with the other cheeses. It adds a wonderful depth and helps the top brown even more beautifully. You can also swap out yellow squash for zucchini or use a combination of both.
Serving Suggestions
This casserole shines as a hearty side dish alongside grilled chicken, pork chops, or a simple green salad. It is also substantial enough to serve as a meatless main course. Leftovers — if there are any — reheat beautifully in the oven at 325°F until warmed through, making it just as good the next morning alongside a cup of coffee.
