Preheat the oven to 400°F (200°C). Line a large rimmed baking sheet with parchment paper or set a wire rack over the pan and spray with non-stick cooking spray.

Pat each chicken breast completely dry with paper towels. Pound any thick breasts to an even 1/2-inch thickness using a meat mallet or rolling pin.

In a shallow bowl, whisk together the chosen binder (mayonnaise, sour cream, or melted butter) and 1 tablespoon of the Ranch seasoning until smooth.

In a second shallow bowl, combine the Panko breadcrumbs, remaining Ranch seasoning, and grated Parmesan. Stir to distribute evenly.

Coat each chicken breast thoroughly in the binder mixture, letting any excess drip off. Press the chicken firmly into the breadcrumb mixture on all sides, ensuring the crust fully adheres.

Place the breaded chicken on the prepared baking sheet. Spray the tops lightly with cooking spray. Bake for 25 to 30 minutes until the crust is deep golden brown and an instant-read thermometer reads 165°F at the thickest part.

If adding cheddar cheese, scatter it over the chicken in the last 3 minutes of baking and return to the oven until melted.

Remove from the oven and let the chicken rest for 5 minutes before slicing. Garnish with fresh parsley and serve immediately.