Step 1

Heat the oven to 425°F and line a baking sheet with foil. Arrange a rack in the middle of the oven and heat to 425°F. Line a rimmed baking sheet with aluminum foil.

Step 2

Butterfly the chicken breasts. Cut each chicken breast in half horizontally (also known as butterflying). Pat the chicken dry with paper towels. This is just a little extra insurance so that the coating will stick well.

Step 3

Toast the panko in the oven. Place the panko on the prepared baking sheet, add the oil, and toss to coat. Spread into an even layer. Toast in the oven until golden-brown, stirring halfway through, 3 to 4 minutes total; set aside to cool.

Step 4

Combine the egg, mayo, salt, and garlic powder. Place the egg, mayonnaise, salt, and garlic powder in a large bowl and whisk until smooth; set aside.

Step 5

Move the panko to a shallow dish and add the Parmesan. Transfer the cooled panko to a pie plate or other shallow dish, add the Parmesan, and stir to combine.

Step 6

Bread the chicken. Place the chicken in the egg mixture and toss with tongs until well-coated. Working with one piece of chicken at a time, press the chicken into the panko until coated on all sides. Place the coated chicken on the baking sheet. You may have leftover breadcrumbs.

Step 7

Bake 15 to 20 minutes. Bake until the chicken is cooked through, crisp, and golden-brown, 15 to 20 minutes.

Step 8

Bake with the marinara sauce and cheese. Remove the baking sheet from the oven. Pour the marinara evenly over the chicken. Sprinkle the chicken with the mozzarella. Bake until the cheese is melted and golden-brown, about 5 minutes more. Serve with cooked pasta and more marinara, if desired.