Prep the zucchini: Preheat your oven to 400°F (200°C). Grate the zucchini on the large holes of a box grater. Toss with 1 teaspoon salt and let it sit in a colander for 10–15 minutes. Then squeeze out as much liquid as you can using a clean kitchen towel or paper towels.

Make the zucchini “crust” base: In a bowl, mix the drained zucchini, eggs, Parmesan, garlic powder, and half the Italian seasoning. The mixture should look thick and a little sticky.

Par-bake the base: Lightly grease a 9x13-inch baking dish with olive oil or spray. Press the zucchini mixture firmly and evenly into the dish. Bake for 12–15 minutes until set and just starting to turn golden at the edges.

Cook the protein: While the base bakes, heat a skillet over medium. Add the ground turkey or chicken, onion, and a pinch of salt. Cook, breaking it up with a spoon, until browned and cooked through, 6–8 minutes. Stir in the minced garlic and the remaining Italian seasoning. Cook 1 minute until fragrant.

Add the sauce: Pour in the marinara or pizza sauce and let it simmer for 2–3 minutes. Taste and adjust salt or add red pepper flakes if you want heat.

Layer it up: Remove the zucchini base from the oven. Spread the meat sauce evenly over the top. Add mushrooms and peppers if using. Sprinkle mozzarella over everything. Add turkey pepperoni or sausage on top for a classic pizza vibe.

Bake until bubbly: Return the dish to the oven and bake 12–15 minutes, until the cheese is melted and lightly browned.

Rest and serve: Let the casserole rest 5–10 minutes so it sets and slices cleanly. Garnish with fresh basil and serve in squares.