Mix the breadcrumbs, grated Parmesan cheese, garlic powder, oregano, salt, and pepper in a bowl.
3.
Lightly brush the chicken breasts with oil and coat them in the mixture of breadcrumbs and Parmesan.
4.
Place the chicken on the baking sheet and bake for 20 minutes, until cooked through and golden brown.
5.
Take the tray out of the oven and cover each chicken breast with a spoonful of tomato sauce and a slice of mozzarella. Bake for 3-5 minutes more, until the cheese is melted and lightly browned. Serve hot.