Preheat the oven to 375°F (190°C). Gather ingredients and baking dish.

Slice zucchini into 1/4-inch rounds, sprinkle with salt, and let sit in colander for 10 minutes.

Layer half of the zucchini in the baking dish, cover with half the marinara, and sprinkle with half the mozzarella and Parmesan.

Repeat the layering process with the remaining zucchini, marinara, mozzarella, and Parmesan.

Mix breadcrumbs with olive oil and seasonings, then sprinkle over the top layer of cheese.

Bake in the preheated oven for 30 minutes until golden brown and bubbling.

Let the dish rest for 5 minutes before serving.