A late summer staple my grandmother made whenever the garden overflowed. Simple, filling, and more comforting than people expect for just 4 ingredients.

This 4-ingredient zucchini casserole is the kind of practical, comforting dish that shines when the garden is producing more zucchini than anyone knows what to do with. It’s a humble baked casserole with a long Midwestern, home-cook sensibility: a few simple ingredients, a hot oven, and a result that feels much richer and cozier than you’d expect. The zucchini softens into tender layers, the cheese gives it body, and the buttery cracker topping turns golden and crisp for a reliable late-summer supper or potluck side.

Serve this casserole alongside roast chicken, grilled pork chops, meatloaf, or simple hamburgers for an easy dinner. It also works nicely with sliced tomatoes, a crisp green salad, or fresh corn on the cob if you want to keep the meal seasonal. For brunch or lunch, I like it with scrambled eggs or a bowl of soup, since the casserole is soft, savory, and substantial without being too heavy.

4-Ingredient Zucchini Casserole

Servings: 6

Ingredients

4 medium zucchini, thinly sliced
2 cups shredded yellow cheddar cheese
1 sleeve buttery round crackers, crushed
4 tablespoons butter, melted

Sliced zucchini, shredded cheddar, crackers, and melted butter

Directions

1. Preheat the oven to 375°F and lightly butter or spray a medium rectangular baking dish.

Prepared baking dish on a kitchen counter

2. Spread half of the sliced zucchini in the baking dish. Sprinkle over half of the cheddar cheese. Add the remaining zucchini in an even layer, then top with the rest of the cheese.

Layered zucchini and cheddar in a glass baking dish

3. In a small bowl, toss the crushed crackers with the melted butter until evenly coated, then scatter the crumb mixture over the top of the casserole.

Buttery cracker crumbs topping the casserole before baking

4. Bake for 30 to 35 minutes, until the zucchini is tender, the cheese is melted, and the topping is deep golden brown. Let stand for 5 to 10 minutes before serving.

Plated zucchini casserole with simple side salad

Variations & Tips

Add onion: If you don’t mind moving beyond the strict four-ingredient version, a thinly sliced sweet onion layered with the zucchini adds a lot of flavor and a little extra sweetness as it bakes.

Zucchini casserole variation with sliced onion layers

Salt the zucchini if needed: Very large or extra-mature zucchini can release quite a bit of water. If yours seem especially wet, toss the slices with a little salt, let them sit for 15 minutes, then pat dry before assembling the casserole.

Change the cheese: Cheddar gives the casserole a classic flavor, but Colby, Monterey Jack, or a cheddar-Jack blend all melt nicely and keep the dish family-friendly and mild.

Keep the topping crisp: For the best texture, serve the casserole soon after its short resting time. That way the cracker topping stays crisp while the inside remains soft and creamy.