This Zucchini Pizza Casserole became one of my go-to weeknight solutions the first time I tried to satisfy pizza cravings without hauling out dough. I discovered the idea during a busy summer when my garden zucchini were multiplying by the day and I wanted something warm, filling, and familiar. The result is a crisp-topped, tender vegetable base that holds up to a robust meat-and-vegetable topping—every bite echoes classic pizza flavors but with less starch and more garden-fresh texture.

I first served this at a casual Sunday supper and watched skeptical kids and adults alike go back for seconds. The zucchini base browns at the edges and stays slightly moist inside, providing a neutral platform that lets the pizza sauce, browned beef, and cheeses shine. It’s the kind of recipe that feels indulgent while leaning on vegetables, and it’s forgiving enough that small swaps—different cheeses or a leaner beef—don’t derail the dish.

Ingredients

• Shredded zucchini (4 cups): Look for medium-sized zucchini with taut skin and firm flesh. Shred on the large holes of a box grater or in a food processor; squeezing out moisture is essential for a sturdy base.
• Large eggs (2): Provide binding and structure. Use room-temperature eggs to help the mixture come together smoothly and set evenly during baking.
• Parmesan cheese (1/2 cup, grated): Adds savory, nutty depth and helps firm the crust. Freshly grated Parm (not pre-grated powder) yields better melt and flavor.
• Mozzarella cheese (2 cups shredded, divided): Use low-moisture whole-milk mozzarella for the best melting and pull; reserve half for the crust and the rest for topping.
• Cheddar cheese (1 cup shredded): Sharp cheddar gives color and a tangy counterpoint to mozzarella—mixing cheeses builds a more complex flavor profile.
• Ground beef (1 pound): Brown and drain before adding sauce. Choose 80/20 for flavor, or 90/10 for lower fat; both work well once you drain excess fat.
• Pizza sauce (2 cups): Use a good-quality jarred sauce or homemade marinara. The sauce adds acidity and herby notes—avoid overly sweet varieties if you prefer a savory finish.
• Vegetables: 1/2 cup chopped onion, 1 green bell pepper (chopped), and 1/2 cup sliced mushrooms provide texture, color, and savory balance to the meat and cheese.
• Seasonings: 1/2 teaspoon salt, 1/2 teaspoon dried oregano, 1/2 teaspoon garlic powder, and 1/4 teaspoon black pepper; they mirror traditional pizza spice without dominating.

Instructions

Step 1 — Preheat and prepare: Preheat your oven to 400°F (200°C). Grease a 9x13-inch baking dish with a thin coat of oil or nonstick spray to ensure easy release. Make sure your oven racks are mid-height for even browning. Step 2 — Drain the zucchini: Combine 4 cups shredded zucchini and 1/2 teaspoon salt in a large bowl and let sit for 10 minutes to draw out moisture. Afterward, transfer the zucchini to a clean kitchen towel or cheesecloth and squeeze firmly until the majority of liquid is expelled—this step prevents a soggy base and helps the crust bind and brown. Step 3 — Make the base mixture: Return the drained zucchini to the bowl and add 2 large eggs, 1/2 cup grated Parmesan, and 1 cup (half of 2 cups) shredded mozzarella. Mix thoroughly until the mixture feels cohesive; the eggs and cheese act as the set agents in place of flour. Step 4 — Form and bake the crust: Press the zucchini mixture evenly into the prepared 9x13-inch dish to form a compact layer about 1/2 to 3/4 inch thick. Bake in the preheated 400°F oven for 20 minutes, or until edges are lightly browned and the interior feels set when you gently press it. These visual cues indicate that the crust will hold toppings without collapsing. Step 5 — Cook the topping: While the crust bakes, brown 1 pound ground beef with 1/2 cup chopped onion in a skillet over medium heat until no pink remains. Drain excess fat. Stir in 2 cups pizza sauce, 1 chopped green bell pepper, 1/2 cup sliced mushrooms, 1/2 teaspoon dried oregano, 1/2 teaspoon garlic powder, and 1/4 teaspoon black pepper. Simmer for 4–5 minutes to meld flavors and remove excess moisture from the vegetables. Step 6 — Assemble and finish baking: Spread the meat-and-vegetable mixture evenly over the baked zucchini base. Sprinkle the remaining 1 cup mozzarella and all of the shredded cheddar evenly across the top. Return the casserole to the oven and bake another 20 minutes at 400°F, until the cheese is fully melted and bubbling and the top has turned golden in spots. Step 7 — Rest and serve: Remove from the oven and let rest for 5–10 minutes—this short cooling period helps the layers set so slices hold together neatly. Slice into squares and serve warm.

Storage Tips

To store, cool the casserole completely, then cover tightly with plastic wrap or transfer to an airtight container. Refrigerate for up to 4 days. For longer storage, freeze individual slices or the whole dish for up to 3 months—wrap in plastic and a layer of foil to prevent freezer burn. Reheat frozen portions in a 350°F oven for 20–30 minutes covered, or microwave single servings for 2–3 minutes followed by 1–2 minutes in a skillet to restore a bit of crust texture. Always check for even reheating so the center reaches a safe temperature before serving.

Ingredient Substitutions

Swap ground turkey or Italian sausage for beef to vary fat content and flavor; turkey keeps the dish leaner while sausage adds spice. For a vegetarian option, use cooked lentils, tempeh crumbles, or a plant-based meat substitute—adjust seasoning and drain any excess moisture. If you prefer less dairy, reduce the cheddar to 1/2 cup and increase Parmesan to 3/4 cup for savory punch, though texture will change slightly. Gluten-free is naturally achieved with this base; just verify your pizza sauce is free of added thickeners containing gluten.

Serving Suggestions

Serve slices with a crisp green salad dressed in lemon vinaigrette or a simple arugula toss to cut through the richness. For family dinners, pair with roasted garlic bread or a light coleslaw. Garnish with fresh basil, red pepper flakes, or a drizzle of extra-virgin olive oil to elevate presentation. This casserole fits casual weeknight meals, potlucks, or a relaxed Sunday supper—slice into squares and let guests help themselves for an informal, communal feel.

Cultural Background

While not a traditional dish from any single region, this casserole draws on the global love of pizza and the American tradition of casseroles—an adaptable, one-dish format designed for feeding families with minimal fuss. The idea of using vegetables as a base reflects contemporary home-cooking trends toward lower-carb options and creative vegetable utilization, particularly in seasons when zucchini is abundant. It’s an example of how classic flavors (tomato, oregano, melted cheese) can be reinterpreted with seasonal produce.

Seasonal Adaptations

Summer garden zucchini are ideal, but in cooler months substitute with summer squash or a mix of shredded cauliflower and zucchini for a similar texture. In fall and winter, swap bell pepper for roasted red peppers and add a handful of chopped spinach or kale to the topping. For holiday gatherings, dress it up with a sprinkle of toasted pine nuts and fresh chopped parsley just before serving.

Meal Prep Tips

Prepare the topping up to 2 days ahead and refrigerate. Squeeze and drain the zucchini, then store it wrapped tightly in the refrigerator until ready to combine with eggs and cheese. If you want breakfast-for-dinner the next day, assemble the crust and par-bake it, then finish with the topping and bake when convenient. Use shallow, meal-prep containers for individual portions—reheat in a toaster oven or skillet to bring back some crispness on the edges.

In short, this casserole is an excellent bridge between comfort and freshness—easy to make, simple to scale, and full of the familiar flavors people always look for. Try it once and you’ll find a dozen small ways to make it your own.