Preheat your oven to 400°F (200°C) and prepare a baking sheet by lining it with parchment paper.
In a shallow bowl, combine the whole wheat breadcrumbs, grated Parmesan cheese, Italian seasoning, garlic powder, salt, and black pepper.
Drizzle the olive oil over the chicken breasts, ensuring they are well coated.
Dredge each chicken breast in the breadcrumb mixture, pressing gently to adhere the crumbs evenly to the chicken.
Place the coated chicken breasts on the prepared baking sheet, ensuring they are spaced apart.
Bake in the preheated oven for 20-25 minutes, or until the chicken is cooked through and the internal temperature reaches 165°F (75°C).
Remove the chicken from the oven and spoon marinara sauce evenly over each piece, then sprinkle with shredded mozzarella cheese.
Return the chicken to the oven and bake for an additional 5-7 minutes, or until the cheese is melted and bubbly.
Let the chicken Parmesan rest for a few minutes before serving to allow the juices to redistribute.