Preheat oven to 450° F. Spray a baking sheet lightly with nonstick cooking spray or olive oil.
Combine the Panko, Parmesan cheese, salt, pepper, garlic powder, and the olive oil in a shallow dish until well combined. Whisk the egg in another shallow dish until well beaten.
Dip the chicken breast into the egg and then into the Panko mixture, carefully pressing the Panko mixture onto the chicken. Place the coated chicken breast onto the baking sheet and repeat with the remaining chicken. Bake in the oven until the chicken is golden brown and registers 165º F when checked with an internal temperature probe, about 25 minutes.
Remove from oven, spoon about 1-2 tablespoons of the marinara sauce over each piece of chicken and top each with shredded mozzarella cheese. Bake until the cheese is melted, about 5 more minutes. Top with fresh basil for serving.