Preheat your oven to 190 °C (375 °F). In a large bowl, stir together the shredded chicken, marinara sauce, ricotta cheese, dried basil, dried oregano, salt, and pepper until the mixture is smooth and evenly blended. This creamy base will form the foundation of your casserole and give it that classic chicken Parmesan flavor.

Spread half of the chicken mixture in the bottom of a greased 9×13-inch baking dish. Sprinkle half of the shredded mozzarella and half of the grated Parmesan evenly over this layer. These layers of cheesy goodness are what make this casserole rich, protein-packed, and satisfying.

Evenly spread the remaining chicken mixture over the cheese layer, then top with the remaining mozzarella and Parmesan. Sprinkle the whole wheat breadcrumbs over the very top so you’ll get a lightly crunchy finish once baked. You’re layering flavor and texture here, so take your time for even distribution.

Bake in the preheated oven for about 25–30 minutes, or until the cheese is melted, bubbly, and golden brown. Let the casserole cool for a few minutes before serving so it sets up and slices cleanly. This is the perfect moment to breathe in that rich aroma.