Preheat the oven to 400°F (200°C). Lightly grease a baking sheet or line it with parchment paper.
In a shallow bowl, combine the whole wheat breadcrumbs, grated Parmesan cheese, garlic powder, dried Italian seasoning, salt, and black pepper.
In a separate shallow bowl, beat the eggs until smooth.
Pat the chicken breasts dry with paper towels. Dip each chicken breast into the beaten eggs, allowing excess to drip off, then coat thoroughly with the breadcrumb mixture. Press the breadcrumbs onto the chicken to ensure they stick well.
Heat the olive oil in a large skillet over medium heat. Add the breaded chicken breasts and cook for 2-3 minutes on each side until golden brown. Remove from heat.
Place the browned chicken breasts on the prepared baking sheet. Spoon 1/4 cup of marinara sauce evenly over each chicken breast.
Sprinkle 1/4 cup shredded mozzarella cheese on top of the sauce on each chicken breast.
Bake in the preheated oven for 15-20 minutes, or until the chicken is cooked through (internal temperature reaches 165°F or 74°C) and the cheese is melted and bubbly.
Remove from the oven and let rest for 5 minutes. Garnish with fresh basil leaves if desired before serving.