Prepare the following, adding each to a 9x13-inch baking dish as you complete it: Finely grate 4 garlic cloves. Juice 1 to 2 medium lemons until you have ¼ cup. Add 3 tablespoons olive oil, 2 teaspoons of the kosher salt, and ½ teaspoon black pepper. Stir to combine.

Working with 1 boneless, skinless chicken breast at a time, cut 4 chicken breasts in half horizontally (also known as butterflying). Pat dry with paper towels. Add the chicken to the baking dish, and flip to coat in the garlic mixture. Let sit at room temperature for 15 minutes.

Meanwhile, set up the dredging station. Place 4 large eggs, 1 tablespoon onion powder, 1 tablespoon garlic powder, 1 tablespoon water, and ½ teaspoon of kosher salt in a wide, shallow bowl or pie plate and whisk to combine. Place 1 cup all-purpose flour and the remaining ½ teaspoon kosher salt in a second shallow bowl and stir to combine. Place 3 cups panko breadcrumbs in a third shallow bowl.

Fit a wire rack over a baking sheet. Working with 1 piece of chicken at a time, dip in the flour mixture until evenly coated. Place in the egg mixture and turn to coat, letting the excess drip back into the dish. Place in the breadcrumbs and flip to coat, gently pressing the breadcrumbs into the chicken so they stick. Place on the wire rack in a single layer. Refrigerate for at least 30 minutes or up to 8 hours.

Grate 12 ounces low-moisture mozzarella cheese on the large holes of a box grater (about 3 cups). Grate 4 ounces Parmesan cheese on the small holes of the grater (about 1 ¾ cups), or measure out 1 cup store-bought grated. Place both cheeses in a medium bowl and stir to combine. Line a second baking sheet with paper towels.

Arrange a rack in the upper third of the oven and heat the broiler. Heat 1-inch canola oil (3 to 5 cups) in a large, high-sided skillet over medium-high heat until 400ºF. Fry in batches of 2 to 3 chicken pieces. Place in the hot oil and fry, until the chicken is cooked through, golden-brown all over, and crisp, 2 to 3 minutes per side. Transfer to the paper towels on the baking sheet.

Remove the paper towels and place the chicken directly on the baking sheet in a single layer. Spoon about ¼ cup marinara sauce onto each piece, leaving the edges uncovered. Sprinkle the cheese mixture evenly over the cutlets.

Broil until the cheese is melted and browned in spots, about 4 minutes. Meanwhile, pick the leaves and tender stems from 6 fresh parsley sprigs, then finely chop.

Sprinkle the chicken with the parsley. Serve with cooked spaghetti and more marinara sauce, if desired.