In a large bowl, whisk together the buttermilk, chopped rosemary, thyme leaves, minced garlic, 1 teaspoon of kosher salt, and 1 teaspoon of black pepper. Add the chicken pieces, ensuring they are fully submerged in the marinade. Cover and refrigerate for at least 4 hours, or preferably overnight.

In a shallow dish or a large resealable bag, combine the all-purpose flour, smoked paprika, onion powder, garlic powder, cayenne pepper, the remaining 1 teaspoon of kosher salt, and the remaining 1 teaspoon of black pepper. Mix well to create the seasoned flour coating.

Remove chicken pieces from the buttermilk marinade, letting any excess drip off. Dredge each piece thoroughly in the seasoned flour mixture, pressing gently to ensure a good coating. Place the coated chicken on a wire rack set over a baking sheet.

Heat the vegetable oil in a large, heavy-bottomed pot or Dutch oven over medium-high heat until it reaches 177 °C (175 °C). Ensure there is enough oil to submerge the chicken pieces without overcrowding the pot.

Carefully place 3-4 pieces of coated chicken into the hot oil, being careful not to overcrowd the pot. Fry for about 6-8 minutes per side, or until deeply golden brown and cooked through. The internal temperature should reach 74 °C (74 °C).

Remove the fried chicken from the oil using a slotted spoon or tongs and place it on a clean wire rack set over a baking sheet to drain excess oil. Repeat with the remaining chicken pieces, maintaining the oil temperature between batches.

Serve the crispy herb-marinated fried chicken hot, accompanied by your favorite sides.