Zucchini casserole is a warm, cheesy baked dish that turns simple sliced zucchini into a comforting side worthy of any dinner table. Layered with a creamy, cheesy sauce and topped with a buttery cracker or breadcrumb topping, it’s a great way to use up a lot of zucchini while making something the whole table will actually want to eat.
Why This Recipe Works
Pre-cooking the zucchini slightly and draining off excess moisture prevents a watery casserole, while a rich, cheesy sauce and a crunchy topping give it that classic comfort-food appeal. It’s a great side dish for potlucks, holidays, or a simple weeknight dinner.
Ingredients
For the casserole
- 4 cups zucchini, sliced into ¼-inch rounds
- 1 teaspoon salt, for drawing out moisture
- 1 tablespoon butter
- ½ medium onion, diced
- 1 (10.5-ounce) can cream of chicken or cream of mushroom soup (or a homemade white sauce)
- ½ cup sour cream
- 1 cup shredded cheddar cheese
- ¼ teaspoon black pepper
- ¼ teaspoon garlic powder
For the topping
- 1 cup crushed buttery crackers (such as Ritz) or panko breadcrumbs
- 3 tablespoons unsalted butter, melted
Equipment
- A 9×13-inch or 2-quart baking dish
- A colander
- A large skillet
- A mixing bowl
Instructions
Step 1: Salt and drain the zucchini
Place the sliced zucchini in a colander, sprinkle with salt, and let sit for 15-20 minutes to draw out excess moisture. Pat dry with a clean towel or paper towels.
Step 2: Sauté the zucchini and onion
Preheat your oven to 350°F (175°C). Melt the butter in a large skillet over medium heat. Add the diced onion and cook for 3-4 minutes, until softened. Add the drained zucchini and cook for another 4-5 minutes, until just tender but not mushy.
Step 3: Make the creamy sauce
In a mixing bowl, combine the cream soup, sour cream, half of the shredded cheese, pepper, and garlic powder.
Step 4: Combine
Fold the sautéed zucchini and onion into the creamy sauce mixture, stirring until evenly coated.
Step 5: Assemble
Pour the zucchini mixture into a greased 9×13-inch or 2-quart baking dish, spreading it into an even layer. Sprinkle the remaining shredded cheese over the top.
Step 6: Make the topping
In a small bowl, combine the crushed crackers or breadcrumbs with the melted butter, tossing until evenly coated. Sprinkle the topping evenly over the casserole.
Step 7: Bake
Bake for 25-30 minutes, until the casserole is bubbly around the edges and the topping is golden brown.
Step 8: Cool slightly and serve
Let the casserole rest for about 5-10 minutes before serving.
Tips for the Best Zucchini Casserole
- Don’t skip salting and draining the zucchini — this step is essential for preventing a watery casserole.
- Don’t overcook the zucchini during sautéing, since it will continue cooking in the oven and can turn mushy if pre-cooked too much.
- Make your own white sauce in place of canned soup if you prefer — a simple roux of butter, flour, and milk works well as a substitute.
- Add crumbled bacon to the topping for extra flavor and texture.
- Assemble ahead of time and refrigerate, adding the topping just before baking, for an easy make-ahead side dish.
Storage
Store leftover casserole covered in the refrigerator for up to 4 days. Reheat in the oven at 350°F until warmed through, or in the microwave for a quicker option.
Final Thoughts
Zucchini casserole is a comforting, crowd-pleasing way to use up extra zucchini, combining a creamy, cheesy filling with a crunchy, buttery topping. It’s an easy side dish to bring to potlucks or holiday dinners, and it’s simple enough for a weeknight side too.
