Preheat oven to 350 degrees F.
Lightly grease a baking dish with nonstick cooking spray and set aside.
Place chicken breasts in a large freezer bag or between two sheets of plastic wrap. Using a rolling pin, or the bottom of a mason jar, whack the thickest part of the chicken to to even out the thickness and tenderize the meat. Set aside.
In a pie plate or shallow dish, add the breadcrumbs, Italian seasoning, garlic powder, and 6 Tablespoons of Parmesan cheese and mix well. In a separate pie plate or shallow dish, add the egg, water, salt, and pepper and whisk. Add the chicken breasts and turn over with thongs to cover all sides of the chicken.
Using tongs, dip a chicken breast into the egg mixture and let the excess drip off. Next, place into the breadcrumb mixture and gently press, making sure to cover all areas of the chicken. Repeat with each breast. and lay in a non-stick skillet with a couple of tablespoons of oil.
Heat a nonstick skillet over medium heat and add about 1-2 tablespoons of olive oil. Add the breaded chicken and cook until golden brown, or about 3-5 minutes. Flip and continue to cook on the other side until golden brown.
Place the browned chicken into the prepared baking dish and cover with the marinara sauce. Sprinkle evenly with mozzarella and Parmesan cheese.
Bake in the preheated oven for about 15 minutes, or until the internal temperature of the chicken reads 165 degrees F. and the cheese is melted. (Note: If the chicken is done before the cheese is melted, place in the broiler for 1-2 minutes)
Remove from the oven and let cool for a few minutes. Garnish with minced parsley if desired. Enjoy!