Garlic Parmesan Zucchini Casserole

Side shot of a green and white plate with a serving of zucchini casserole.

4.99 from 71 votes

Garlic Parmesan Zucchini Casserole

This cheesy zucchini casserole bakes up tender and golden under a crispy, buttery Parmesan breadcrumb topping. With about 15 minutes of prep, it's an easy way to turn a pile of summer squash into a side that pairs with almost any meal.

Course Side Dish

Cuisine American, Southern

Keyword Baked Zucchini, best zucchini casserole recipe, easy zucchini casserole, old fashioned zucchini casserole, Zucchini Casserole

Prep Time 15

Cook Time 25

Total Time 40

Servings servings

Calories 209kcal

Author Blair Lonergan

Ingredients

4 cups grated zucchini (about 3 ½ medium zucchinis)
½ teaspoon kosher salt
¼ cup finely grated onion
1 tablespoon minced garlic (about 3 cloves)
2 large eggs
½ cup grated Parmesan cheese, plus an additional 2 tablespoons
1 cup shredded mozzarella cheese
½ cup shredded cheddar cheese
½ cup Panko breadcrumbs
1 tablespoon salted butter, melted

Instructions

Preheat the oven to 375°F. Grease a 1 ½-quart baking dish and set aside.
Salt and drain the zucchini. Place the grated zucchini in a colander, sprinkle with the salt, and let it sit for about 10 minutes. Squeeze out the moisture by wrapping the zucchini in a dish towel and wringing it out a few times. The drier the zucchini, the better the casserole.
Mix the filling. In a large bowl, combine the drained zucchini, onion, garlic, eggs, ½ cup Parmesan, mozzarella, and cheddar. Gently press the mixture evenly into the prepared dish.
Bake uncovered for 20 minutes.
Make the topping. Meanwhile, in a small bowl, stir the melted butter into the panko breadcrumbs and 2 tablespoons of Parmesan until combined.
Top and finish baking. Sprinkle the breadcrumbs over the casserole and return it to the oven for 5 to 10 more minutes, until the top is golden brown and crisp.
Garnish with fresh herbs or a squeeze of lemon and let rest a few minutes before serving.

Video

Notes

Drying matters most. A salad spinner lined with paper towels works well, and salting the zucchini hours ahead to drain gives an even drier start.
Grating: A handheld box grater works, or run the zucchini through a food processor. No need to peel.
Cheese swaps: Use an equal amount of just mozzarella or just cheddar, or try Monterey Jack, Colby Jack, Pepper Jack, Gruyere, Swiss, or Gouda.
Yellow squash: Swap in yellow summer squash for some or all of the zucchini. A little shredded carrot is a nice addition too.
For more kick: Add black pepper, crushed red pepper, or a teaspoon of Italian seasoning to the filling.
Topping twist: Toss the breadcrumbs with olive oil instead of butter for a different flavor.
To double: Double everything and bake in a larger dish, adding a few minutes to the bake time.

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