This Cheesy Zucchini Pizza Casserole is a quick high-protein meal with lean ground turkey, fresh zucchini, and gooey mozzarella. Perfect for busy weeknights!

Ingredients

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Instructions

Step 1

Preheat your oven to 375°F (190°C). While the oven heats, gather all your ingredients. This is the perfect time to dice the onion, mince the garlic, and slice the zucchini into uniform 1/4-inch rounds. Uniform slices ensure even cooking and a beautiful layered presentation. Set the zucchini aside on a paper towel-lined plate and lightly salt them to draw out excess moisture, which prevents a watery casserole. Pat dry after 5 minutes.

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Step 2

Heat olive oil in a large skillet over medium-high heat. Add the ground turkey and cook, breaking it apart with a wooden spoon, until browned and cooked through, about 5-7 minutes. The meat should be no longer pink and reach an internal temperature of 165°F. Use a slotted spoon to transfer the turkey to a plate, leaving a little fat in the pan for flavor.

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Step 3

Reduce the heat to medium and add the diced onion to the same skillet. Sauté for 3-4 minutes until translucent and fragrant. Add the minced garlic and cook for another 30 seconds until aromatic, being careful not to burn the garlic. Stir in the dried oregano, basil, red pepper flakes (if using), salt, and black pepper. Cook for 1 minute to toast the spices and unlock their essential oils.

Step 4

Pour the marinara sauce into the skillet and stir to combine with the onion and spices. Bring the sauce to a gentle simmer, then return the cooked ground turkey to the pan. Stir everything together and let it simmer for 5 minutes to meld the flavors. The sauce will thicken slightly. Taste and adjust seasoning if needed.

Step 5

Now it’s time to assemble the casserole. Lightly grease a 9×13-inch baking dish with cooking spray or olive oil. Spread a thin layer of the turkey marinara sauce (about 1/2 cup) on the bottom of the dish to prevent sticking. Arrange a layer of zucchini slices over the sauce, overlapping slightly. Spoon half of the remaining sauce over the zucchini, then sprinkle with 1 cup of mozzarella cheese and half of the Parmesan. Repeat with another layer of zucchini, remaining sauce, and top with the remaining mozzarella and Parmesan.

Step 6

Place the baking dish in the preheated oven and bake for 20-25 minutes, until the cheese is bubbly and golden brown, and the zucchini is tender when pierced with a fork. If you want a deeper golden crust, switch to broil for the last 2 minutes, watching carefully to avoid burning. Let the casserole rest for 5 minutes before slicing. Garnish with fresh basil if desired. Serve hot and enjoy the incredible flavors of pizza without the carbs!

For best results

  • To prevent a watery casserole, salting the zucchini is a game-changer. After slicing, lay the rounds on a paper towel-lined baking sheet, sprinkle with salt, and let them sit for 10-15 minutes. The salt draws out excess moisture that would otherwise release during baking and make your casserole soggy. Pat the zucchini dry with another paper towel before layering. This simple step ensures a firm, tender texture that holds up beautifully.
  • For the best flavor, choose a high-quality marinara sauce with no added sugar. Look for brands that use San Marzano tomatoes and have a short ingredient list. Alternatively, you can make your own quick sauce by blending canned crushed tomatoes with sautéed garlic, oregano, and a pinch of red pepper flakes. Homemade sauce allows you to control the sodium and sweetness.
  • Lean ground turkey (93/7) keeps this dish macro-friendly while providing ample protein. If you prefer a richer flavor, you can substitute ground chicken or lean ground beef (90/10). For a vegetarian version, use crumbled plant-based meat or cooked lentils. The cooking time remains the same, but ensure any meat substitute is fully cooked before assembling.
  • Shred your own mozzarella from a block for the best melt and flavor. Pre-shredded cheeses often contain anti-caking agents like cellulose or potato starch, which can prevent smooth melting and a creamy texture. A block of part-skim mozzarella is also lower in fat and calories, aligning with your macro goals.
  • This casserole is perfect for meal prep. Assemble it completely (without baking), cover tightly with foil, and refrigerate for up to 2 days before baking. When ready to eat, bake as directed, adding 5-10 minutes to the cooking time since it starts cold. You can also freeze the unbaked casserole for up to 3 months. Thaw overnight in the refrigerator before baking.
  • To achieve a beautiful golden cheese crust, broil the casserole for the last 2-3 minutes of baking. Keep a close eye on it because broilers vary in intensity. The cheese should bubble and develop brown spots without burning. Let the casserole rest for 5 minutes after broiling to allow the cheese to set slightly, making it easier to slice.
  • If you're following a low-carb or keto diet, this recipe is easily adaptable. Use full-fat mozzarella and add extra Parmesan. You can also bulk up the protein by adding cooked Italian sausage or pepperoni slices between the layers. The zucchini serves as a fantastic low-carb noodle substitute, keeping the dish satisfying without the carbs.

Variations

  • Vegetarian Option: Omit the ground turkey and replace with 1 (15-ounce) can of chickpeas, drained and rinsed, or 1 cup of cooked green lentils. Add them to the sauce along with the marinara. You can also add sliced mushrooms and bell peppers for extra texture. The protein content will be lower, but the fiber will increase, making it a hearty meatless meal.
  • Spicy Pepperoni Pizza Casserole: For a classic pepperoni pizza twist, layer 1/2 cup of turkey pepperoni slices between the zucchini layers. Turkey pepperoni is lower in fat and calories than traditional pepperoni but still delivers that smoky, spicy flavor. Reduce the red pepper flakes to 1/4 teaspoon to balance the heat.
  • Gluten-Free and Keto-Friendly: This recipe is naturally gluten-free, but to make it keto, use full-fat mozzarella and replace the marinara with a low-carb pizza sauce (look for one with 3g net carbs or less per serving). You can also add 1/4 cup of cream cheese to the sauce for extra richness and fat. Serve with a side salad to round out the meal.
  • Cheesy Zucchini Pizza Casserole with Sausage: Swap the ground turkey for 1 pound of spicy or sweet Italian chicken sausage (casings removed). Brown the sausage in the skillet, breaking it into crumbles. The fennel and herbs in the sausage add an incredible depth of flavor that pairs beautifully with the zucchini and mozzarella.
  • White Pizza Zucchini Casserole: For a creamy white pizza version, replace the marinara with a mixture of 1 cup ricotta cheese, 1/2 cup heavy cream, 2 minced garlic cloves, and 1 teaspoon Italian seasoning. Layer the zucchini with this creamy sauce, then top with mozzarella and Parmesan. Bake as directed. This variation is rich, decadent, and lower in carbs.

Nutrition

  • Calories385 kcal
  • Total Fat18g
  • Saturated Fat8g
  • Cholesterol85mg
  • Sodium720mg
  • Total Carbohydrates18g
  • Dietary Fiber4g
  • Sugars10g
  • Protein38g

Common Questions

Can I use yellow squash instead of zucchini?
Absolutely! Yellow squash is a perfect substitute for zucchini in this casserole. It has a similar texture and mild flavor, though it’s slightly sweeter. Follow the same salting and layering process. You can even use a mix of both for a colorful presentation.
How do I store leftovers and how long do they last?
Store any leftover casserole in an airtight container in the refrigerator for up to 4 days. To reheat, place individual portions in the microwave for 1-2 minutes or in a 350°F oven for 10-15 minutes until heated through. The zucchini may soften further upon reheating, but the flavors will meld even more deliciously.
Can I freeze this casserole?
Yes, this casserole freezes wonderfully. Assemble it completely but do not bake. Wrap the dish tightly with plastic wrap, then a layer of aluminum foil. Freeze for up to 3 months. When ready to bake, thaw overnight in the refrigerator, then bake as directed, adding 10-15 minutes to the cooking time since it starts cold. Alternatively, you can bake from frozen: increase the baking time by 20-25 minutes, covering with foil for the first half to prevent over-browning.
Is this recipe suitable for meal prep?
Definitely! This casserole is ideal for meal prep. Prepare it on Sunday and portion it into individual containers for easy grab-and-go lunches or dinners throughout the week. The flavors actually improve after a day or two as they meld together. Pair each serving with a side of steamed vegetables or a fresh salad for a complete meal.
Can I add more vegetables to this casserole?
Absolutely! Feel free to add sliced bell peppers, mushrooms, spinach, or even chopped broccoli. Sauté any hard vegetables like mushrooms or bell peppers with the onion to soften them before layering. For leafy greens like spinach, wilt them in the skillet with the garlic. Just be mindful not to overload the casserole with too many watery vegetables, as that can make it soggy. Stick to about 1-2 cups of extra veggies.
What can I serve with this casserole?
This casserole is a complete meal on its own, but you can serve it with a side of crusty whole-grain bread, a simple green salad with vinaigrette, or roasted vegetables like asparagus or broccoli. For a low-carb option, enjoy it with a side of cauliflower rice or zucchini noodles. The mild flavors of the casserole pair well with almost anything.
Can I use ground beef instead of turkey?
Yes, lean ground beef (90/10 or 93/7) works perfectly in this recipe. It will add a richer, beefier flavor that many associate with traditional pizza. Just be sure to drain any excess fat after browning to keep the casserole from becoming greasy. The cooking time and other ingredients remain the same.