Heat oven to 375°F.
Scatter 2 tablespoons bread crumbs over bottom of 11 x 7 x 1 1/2-inch baking pan. Place half the cauliflower on top. Pour 1-1/2 cups marinara over cauliflower. Sprinkle 1 cup mozzarella cheese and remaining 2 tablespoons bread crumbs over sauce. Repeat layering, ending with mozzarella. Cover with foil.
Bake in 375°F oven for 40 minutes. Remove foil. Sprinkle top with Parmesan. Bake another 15 minutes or until Parmesan is melted and golden. Let stand 15 minutes before serving.