Remove chicken from the brine. Rinse clean under running cold water. Pat dry with paper towels or allow to air-dry. Let it come to room temperature before using.
Fill frying pot with at least 2 inches of oil (do not let oil come to more than ⅓ up sides of pan). Set thermometer in pot and heat oil up to 320° F.
Take two baking sheets. Line both sheets with parchment paper, and set a cooling wire rack over one. Set aside.
To make the flour coating, whisk together flour, garlic powder, onion powder, paprika, cayenne, salt, and pepper. Divide among two shallow bowls. In a third bowl, add buttermilk. Season with salt and pepper.
When the oil is almost at temperature, dip chicken thighs in first bowl of flour. Shake off excess flour, dip into buttermilk and allow excess liquid to go back into the buttermilk bowl. Dip into second bowl of flour, coating both sides of chicken. Place in 1st parchment line baking sheet. Continue with other thigh.
Gently lower thigh into the hot oil. If temperature of oil dips, adjust heat to get back to 320° F. Fry 10-13 minutes, carefully moving the chicken around the oil, keeping track of the oil temperature and turning over chicken as necessary. Cook until coating is golden brown, very crispy, and chicken has an internal temperature of 165 °F. Once thighs are done, transfer to cooling wire rack with the skin-side up. Sprinkle with sea salt and black pepper.
Meanwhile, coat the chicken legs in the same fashion.
Once drumsticks are cooked, increase oil temperature to 340 ° F. Coat chicken breasts and wings. Fry breasts for 7-10 minutes, until cooked through and crisp. Transfer to rack, and season with °salt and pepper. Cook wings for 6-8 minutes.
After you are done frying the chicken, add the rosemary and thyme to the hot oil. Be careful because any moisture/water from the herbs will cause the oil to splatter. Cook for a couple seconds until herbs are crisp and warm. Serve with chicken.