For the Marinade:

• In a medium bowl, combine all ingredients for the marinade. Taste sour cream mixture, adjust salt and add the cayenne pepper if desired. Set aside. To prepare chicken, cut each piece horizontally as evenly as possible. You should have 6 pieces now of similar size and thickness. If your chicken isn’t even, you can use the flat side of a meat mallet, place a sheet of plastic wrap over the chicken and pound down the thicker parts. Make sure to pat the chicken dry then add it and to the marinade in the bowl and mix the chicken until the chicken is completely covered. Seal the bowl with plastic wrap and place in the refrigerator for 2 to 24 hours*
• When ready to cook, preheat the oven to 350 degrees F. Place the cornflakes in a blender and pulse for a few seconds until it's chopped into small pieces, but not a fine powder. Place crumbs in a shallow dish, add parmesan cheese, all seasonings and mix well. Taste the crust mixture and adjust the salt and spices to taste. Drizzle in half the melted butter and mix thoroughly. You don't want to make the crumb mixture too soggy, so add a little at a time.
• Prepare a sheet pan by covering it in foil and spray lightly with cooking spray.  Place sour cream chicken in the cornflake dish and coat both sides well, pressing corn flakes into the chicken. Repeat and pour the remainder of the crumbs and the remaining 3 tablespoons of butter over the chicken. Bake for 25 to 30 minutes or until the chicken reads 165 degrees on a meat thermometer. If the crust is getting too dark but the chicken is still not cooked, cover with foil and continue baking. The amount of time will vary depending on the thickness of your chicken, adjust accordingly.**