Zucchini Casserole (Cheesy Baked Zucchini Bake)

What Makes This Recipe Work

Salting pulls excess water out of the zucchini before it ever hits the oven, which keeps the custard from separating. A quick onion and garlic saute builds a savory base so the mild squash does not taste flat.

Ingredients for Zucchini Casserole (Cheesy Baked Zucchini Bake)

• 2 1/2 lb (1.1 kg) zucchini, sliced 1/4 inch thick (about 6 medium)
• 1 1/2 tsp kosher salt, for draining
• 2 tbsp olive oil
• 1 medium yellow onion, diced
• 2 cloves garlic, minced
• 3 large eggs
• 1 cup (240 ml) whole milk
• 1 cup (120 g) shredded sharp cheddar cheese
• 1/2 cup (50 g) grated Parmesan cheese
• 1/2 cup (60 g) panko breadcrumbs
• 1/4 tsp freshly ground black pepper
• 1/2 cup (50 g) crushed buttery crackers, for topping

How to Make Zucchini Casserole (Cheesy Baked Zucchini Bake)

1. Preheat the oven to 375 F (190 C) and lightly grease a 9x13-inch baking dish.
2. Toss the zucchini slices with 1 1/2 tsp salt in a colander and let them drain 20 minutes, then press dry with paper towels or a clean kitchen towel.
3. Heat the olive oil in a large skillet over medium heat. Cook the onion until soft and translucent, about 5 minutes, then add the garlic and cook 30 seconds until fragrant.
4. In a large bowl, whisk the eggs, milk, and pepper with the cheddar, Parmesan, and panko. Fold in the drained zucchini and the onion mixture until evenly combined.
5. Spread the filling into the prepared dish and scatter the crushed crackers evenly over the top.
6. Bake 30 to 35 minutes, until the center is set and the top is deep golden to lightly bubbling at the edges. A knife inserted in the center should come out clean.
7. Rest the casserole 10 minutes before serving so the slices hold together.

Tips for the Best Zucchini Casserole (Cheesy Baked Zucchini Bake)

• For the driest bake, wrap the salted zucchini in a clean towel and squeeze one handful at a time.
• Taste the filling before baking; the cheeses bring plenty of salt, so season lightly.
• A 9x13 dish gives more surface for browning. For a thicker, softer bake, use an 8x8 dish and add 8 to 10 minutes.

Variations and Substitutions

• Add 1 cup cooked crumbled sausage or browned ground beef for a heartier version.
• Swap the cheddar for Gruyere or Monterey Jack for a nuttier melt.
• For a Southern-style bake, follow the same method as a squash casserole with yellow summer squash and a buttery cracker topping.
• Hollow out large zucchini and use this filling to make stuffed zucchini boats with a shorter 25-minute bake.

How to Store and Reheat

• Cover leftovers and refrigerate up to 4 days, then reheat at 350 F (175 C) until warmed through, about 15 minutes.
• To freeze, bake and cool completely, wrap tightly, and freeze up to 2 months. Thaw overnight in the fridge before reheating.

Zucchini Casserole (Cheesy Baked Zucchini Bake) FAQ