Preheat oven to 475 degrees.
Toast breadcrumbs. Place breadcrumbs in a large skillet and add olive oil. Toast over medium heat until lightly golden brown, stirring often (approximately 10 minutes). Remove from heat.
In Bowl #1: Mix together flour, garlic powder, salt, and pepper.
In Bowl #2: Mix together egg whites and water.
In Bowl #3: Mix together toasted breadcrumbs and parmesan cheese.
Line a baking sheet with aluminum foil and spray cooking spray.
Pat chicken dry with paper towels.
Take each piece of chicken and take it through each bowl in order: flour, then egg, then breadcrumbs.
Place chicken on cookie sheet.
Bake chicken approximately 15 minutes.
Remove from oven and spoon approximately 2 tbsp. marinara sauce over chicken & top with 2 tbsp. mozzarella.
Bake chicken for 5 minutes more until cheese is melted.
Serve over spaghetti noodles with more sauce.