Baked Zucchini Spinach and Feta Casserole Recipe

Baked Zucchini Spinach and Feta Casserole Recipe tastes creamy, cheesy, and herby with a golden top and tender veggies in every bite. It works perfectly for busy weeknights or relaxed weekend brunch and takes about 55 minutes from start to finish. I first threw this together on a hot August night when my fridge held nothing but zucchini, spinach, and a block of feta, and it has stayed in my regular rotation ever since.

Why Make This Baked Zucchini Spinach and Feta Casserole Recipe at Home

This casserole packs a lot of flavor into simple, affordable ingredients. Zucchini, spinach, and feta bake into a savory, slightly tangy dish that feels cozy but still light enough for warm weather.

You control the salt, the oil, and the cheese, so the casserole can taste lighter or richer depending on your mood. Leftovers reheat beautifully, so you cook once and enjoy it for breakfast, lunch, or dinner.

“This Baked Zucchini Spinach and Feta Casserole Recipe tastes like spanakopita met a veggie lasagna and decided to become your new favorite weeknight dinner. ★★★★★”

Ingredients You Need

Fresh produce

• 3 medium zucchini, thinly sliced into half moons
  • Choose firm zucchini with shiny skin. Slightly larger ones work too, but scoop out big seeds if they look tough.
• 4 packed cups fresh baby spinach, roughly chopped
  • Frozen spinach works as a shortcut: thaw 10 ounces, then squeeze out as much liquid as possible.
• 1 small yellow onion, finely diced
• 3 cloves garlic, minced

Dairy and eggs

• 1 cup crumbled feta cheese
  • I like sheep’s milk feta for stronger flavor, but any good-quality feta works.
• 1 cup shredded mozzarella or low-moisture provolone
  • Pre-shredded cheese saves time, but block cheese that you shred yourself melts more smoothly.
• ½ cup grated Parmesan cheese
• 3 large eggs
• 1 cup whole milk or half-and-half
  • You can use unsweetened plain oat milk or almond milk if you keep things lighter, but the texture turns slightly less creamy.

Pantry staples and seasonings

• 2 tablespoons olive oil, plus a little more for the baking dish
• ½ cup plain breadcrumbs or panko
  • Italian seasoned breadcrumbs add extra flavor and save a step.
• 1 teaspoon dried oregano
• ½ teaspoon dried thyme
• ½ teaspoon dried basil
• ½ teaspoon smoked paprika or sweet paprika
• ½ teaspoon kosher salt, plus more to taste
• ¼ teaspoon black pepper
• Optional: pinch of red pepper flakes for a little heat

Optional add-ins

• ½ cup cooked quinoa or rice for a heartier casserole
• ½ cup cooked, crumbled breakfast sausage or cooked shredded chicken for extra protein
• ¼ cup chopped fresh parsley or dill for serving

Equipment list

• 9×13 inch baking dish or similar casserole dish
• Large skillet
• Large mixing bowl
• Whisk
• Cutting board and sharp knife
• Colander or clean kitchen towel to drain zucchini
• Measuring cups and spoons

Tips & Mistakes

• Salt the zucchini slices lightly and let them sit 10 to 15 minutes, then pat dry so the casserole does not turn watery.
• Squeeze thawed frozen spinach very well, or the extra moisture will thin the custard and soften the top.
• Use a hot skillet and cook the onion until it turns lightly golden to build flavor instead of leaving it pale and sharp.
• Crumble feta by hand instead of using pre-crumbled if you want bigger pockets of salty cheese.
• Do not overbake; pull the casserole when the center just sets and the top turns golden, or it can dry out.
• Let the casserole rest 10 minutes before cutting so the slices hold together instead of falling apart.
• Taste the filling mixture before baking and adjust salt, since feta and Parmesan already bring a lot of saltiness.
• Grease the baking dish well and sprinkle a thin layer of breadcrumbs on the bottom to prevent sticking and sogginess.

How to Make Baked Zucchini Spinach and Feta Casserole Recipe

Step 1: Prep the zucchini

1. Wash the zucchini and trim the ends.
2. Slice into thin half moons, about ⅛ to ¼ inch thick.
3. Place the slices in a colander, sprinkle with a light pinch of salt, and toss.
4. Let them sit 10 to 15 minutes, then pat dry with paper towels to remove extra moisture.

Step 2: Sauté the aromatics and spinach

1. Heat 2 tablespoons olive oil in a large skillet over medium heat.
2. Add the diced onion and cook 4 to 5 minutes until it turns soft and lightly golden.
3. Stir in the minced garlic and cook 30 seconds until fragrant.
4. Add the chopped spinach in batches and stir until it wilts and cooks down, about 2 to 3 minutes.
5. Turn off the heat and let the mixture cool slightly.

Step 3: Mix the egg and dairy base

1. Crack the eggs into a large mixing bowl and whisk until smooth.
2. Pour in the milk or half-and-half and whisk again.
3. Add feta, mozzarella, Parmesan, oregano, thyme, basil, smoked paprika, salt, black pepper, and optional red pepper flakes.
4. Stir until the cheeses and seasonings distribute evenly.

Step 4: Combine the veggies and filling

1. Add the sautéed spinach and onion mixture to the egg and cheese bowl.
2. Add the drained zucchini slices.
3. If you use cooked quinoa, rice, sausage, or chicken, stir those in now.
4. Gently fold everything together until the zucchini and spinach coat with the egg mixture.

Step 5: Assemble the casserole

1. Preheat your oven to 375°F (190°C).
2. Lightly oil a 9×13 inch baking dish.
3. Sprinkle a couple of tablespoons of breadcrumbs over the bottom of the dish to create a light crust.
4. Pour the zucchini spinach mixture into the dish and spread it into an even layer.
5. Sprinkle the remaining breadcrumbs over the top for extra crunch.

Step 6: Bake

1. Place the casserole on the middle rack of the oven.
2. Bake 30 to 35 minutes until the top turns golden and the center feels set when you jiggle the dish gently.
3. If the top browns too quickly, tent the dish loosely with foil and continue baking.
4. Remove from the oven and let it rest 10 minutes before slicing.

Step 7: Finish and serve

1. Sprinkle chopped fresh parsley or dill over the top if you like a fresh herbal note.
2. Cut into squares and serve warm.
3. Enjoy as a main dish or as a side alongside your favorite protein or salad.

Variations I've Tried

• Tomato twist: Add a layer of thinly sliced tomatoes on top before sprinkling breadcrumbs. The tomatoes roast and add a sweet, juicy layer that pairs nicely with feta.
• Low carb version: Swap the breadcrumbs for a mix of grated Parmesan and almond flour. The top still turns golden and crisp while keeping carbs lower.
• Extra protein: Stir in cooked ground turkey or shredded rotisserie chicken. This turns the Baked Zucchini Spinach and Feta Casserole Recipe into a full one-pan meal.
• Herb lover version: Add fresh dill, parsley, and a little mint to the filling. The flavor leans more Mediterranean and tastes bright and fresh.
• Spicy version: Add extra red pepper flakes and a pinch of cayenne to the egg mixture. The gentle heat balances the creamy cheese and mild zucchini.

How to Serve Baked Zucchini Spinach and Feta Casserole Recipe

Serve this Baked Zucchini Spinach and Feta Casserole Recipe warm with a simple green salad or sliced cucumbers and tomatoes on the side. I like to add a dollop of plain Greek yogurt or a spoonful of tzatziki on top for extra creaminess. You can pack leftovers into lunch containers with some cooked grains and raw veggies for an easy meal. It also works nicely as a brunch dish next to scrambled eggs and fresh fruit.

How to store

• Fridge: Let the casserole cool to room temperature, then cover the dish tightly or transfer slices to airtight containers and refrigerate for up to 4 days.
• Freezer (whole or slices): Wrap the cooled casserole or individual pieces in plastic wrap, then foil, or place in freezer-safe containers and freeze for up to 2 months.
• Reheat from fridge: Reheat slices in a 350°F (175°C) oven for 10 to 15 minutes until hot, or use a skillet with a lid over low heat to warm gently.
• Reheat from frozen: Thaw overnight in the fridge, then bake at 350°F (175°C) for 20 to 25 minutes until heated through, or reheat covered so the top does not overbrown.

Baked Zucchini Spinach and Feta Casserole Recipe

Baked Zucchini Spinach and Feta Casserole is a creamy, cheesy, herby dish with a golden top and tender veggies in every bite, perfect for busy weeknights or relaxed weekend brunch.

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Prep Time 20 minutes mins

Cook Time 35 minutes mins

Total Time 55 minutes mins

Servings: 6

Course: Breakfast, Drinner, Lunch

Ingredients

  

• 3 medium zucchini, thinly sliced into half moons
• 4 cups fresh baby spinach, roughly chopped
• 1 small yellow onion, finely diced
• 3 cloves garlic, minced

• 1 cup crumbled feta cheese
• 1 cup shredded mozzarella or low-moisture provolone
• 1/2 cup grated Parmesan cheese
• 3 large eggs
• 1 cup whole milk or half-and-half

• 2 tablespoons olive oil
• 1/2 cup plain breadcrumbs or panko
• 1 teaspoon dried oregano
• 1/2 teaspoon dried thyme
• 1/2 teaspoon dried basil
• 1/2 teaspoon smoked paprika or sweet paprika
• 1/2 teaspoon kosher salt, plus more to taste
• 1/4 teaspoon black pepper
• 1 pinch red pepper flakes

• 1/2 cup cooked quinoa or rice
• 1/2 cup cooked, crumbled breakfast sausage or shredded chicken
• 1/4 cup chopped fresh parsley or dill, for serving
• olive oil, for greasing the baking dish

Instructions

 

1. Wash the zucchini, trim the ends, and slice into thin half moons about 1/8 to 1/4 inch thick.
2. Place the zucchini slices in a colander, sprinkle lightly with salt, toss, and let sit for 10 to 15 minutes.
3. Pat the zucchini dry with paper towels to remove excess moisture.

1. Heat 2 tablespoons olive oil in a large skillet over medium heat.
2. Add the diced onion and cook for 4 to 5 minutes, until soft and lightly golden.
3. Stir in the minced garlic and cook for about 30 seconds, until fragrant.
4. Add the chopped spinach in batches and cook, stirring, until wilted and cooked down, about 2 to 3 minutes.
5. Remove the skillet from the heat and let the mixture cool slightly.

1. Crack the eggs into a large mixing bowl and whisk until smooth.
2. Whisk in the milk or half-and-half until combined.
3. Add the feta, mozzarella, Parmesan, oregano, thyme, basil, smoked paprika, salt, black pepper, and optional red pepper flakes.
4. Stir until the cheeses and seasonings are evenly distributed.

1. Add the sautéed spinach and onion mixture to the egg and cheese mixture.
2. Add the drained zucchini slices.
3. Stir in cooked quinoa, rice, sausage, or chicken if using.
4. Gently fold everything together until the vegetables are well coated with the egg mixture.

1. Preheat the oven to 375°F (190°C).
2. Lightly oil a 9x13 inch baking dish.
3. Sprinkle a thin layer of breadcrumbs over the bottom of the dish.
4. Pour the zucchini and spinach mixture into the dish and spread into an even layer.
5. Sprinkle the remaining breadcrumbs over the top for extra crunch.

1. Place the casserole on the middle rack of the oven and bake for 30 to 35 minutes, until the top is golden and the center is just set when gently jiggled.
2. If the top browns too quickly, tent the dish loosely with foil and continue baking.
3. Remove from the oven and let rest for 10 minutes so the slices hold together.
4. Sprinkle with chopped fresh parsley or dill if desired, cut into squares, and serve warm as a main or side dish.

Notes

Nutrition Information
Approximate per serving (1/6 of recipe, without optional add-ins): 260–320 calories; fat 18–22 g; saturated fat 9–11 g; carbohydrates 10–14 g; fiber 2–3 g; sugars 5–6 g; protein 14–18 g; sodium 650–850 mg. Values will vary based on exact cheeses, milk choice, breadcrumbs, add-ins, and portion size.