Instructions

1. Arrange 2 racks to divide the oven into thirds and heat the oven to 425°F. Place 2 1/2 cups panko breadcrumbs on a rimmed baking sheet. Drizzle with 3 tablespoons of the olive oil, season with 1/2 teaspoon of the kosher salt, and toss to combine. Spread into an even layer.
2. Bake, stirring halfway through, until the panko is golden brown, 8 to 10 minutes total. Meanwhile, pick the leaves from 1/2 medium bunch fresh parsley, finely chop until you have 3 tablespoons, and place in a large bowl. Finely grate 5 ounces Parmesan cheese (about 1 1/4 cups); add 1 cup to the bowl of parsley and reserve the remaining for sprinkling.
3. When the panko is ready, let cool slightly. Scrape into the bowl with the parsley, add 1/2 teaspoon garlic powder, and stir to combine.
4. Wipe the baking sheet clean with paper towels. Drizzle that baking sheet and a second rimmed baking sheet with the remaining 2 tablespoons olive oil (1 tablespoon each). Brush to evenly coat each baking sheet with oil.
5. Place 4 large eggs in a shallow bowl and whisk until smooth. Place 1/3 cup all-purpose flour in a second shallow bowl.
6. Pat 2 pounds thin-sliced chicken cutlets dry with paper towels. Season all over with the remaining 2 teaspoons kosher salt and 1/2 teaspoon black pepper. Working with one chicken cutlet at a time, coat the cutlet completely in the flour. Dip the floured cutlet in the egg mixture, turning a few times until completely coated and letting the excess egg drip back into the bowl. Place the cutlet in the panko mixture and use your hands to pat the mixture onto the chicken. Place in a single layer on the baking sheets.
7. Bake for 8 minutes. Flip the chicken cutlets. Return to the oven, rotating the baking sheets between racks. Bake until just cooked through, 6 to 9 minutes more. Meanwhile, very thinly slice 12 ounces fresh mozzarella cheese.
8. Remove baking sheets from the oven. Switch the oven to broil on high. Transfer all the chicken onto one of the baking sheets, slightly overlapping them as needed. Spoon heaping 1/4 cup marinara sauce over each cutlet, leaving the edges uncovered (save the remaining marinara for another use). Top with the mozzarella and sprinkle with the remaining Parmesan.
9. Broil on the upper rack until the cheeses on top are melted and bubbly, 5 to 8 minutes.
10. Pick the leaves from 1 small bunch fresh basil and thinly slice until you have 1/2 packed cup. Garnish the chicken with the basil and red pepper flakes if desired.