In a shallow dish, mix together the breadcrumbs and Parmesan cheese. Dredge the chicken breasts first in the flour, then the egg, then the breadcrumbs and Parmesan mixture.
Heat 3 tablespoons of olive oil in a large cast-iron skillet over medium-high heat. Cook the chicken for 5 minutes per side. Remove from pan, add the garlic, chili flakes, marinara and basil. Bring to a simmer. Return chicken and top with mozzarella and more Parmesan. Cover pan and cook until cheese is melted.
In a sauté pan, heat remaining 1 tablespoon olive oil. Add zucchini noodles and cook for 3 minutes.
Plate zucchini noodles and top with sauce and a piece of chicken. Garnish with parsley.