Debone the thighs by placing them skin-side down and carefully cutting along and under the bone with a sharp knife. Keep the skin intact.
Pat all chicken pieces dry with paper towels.
In a large bowl, mix buttermilk, hot sauce, pickle juice, and salt.
Add chicken and coat completely. Cover and refrigerate at least 4 hours or overnight.
In a shallow dish, combine flour, cornstarch, salt, black pepper, onion powder, and AB’s A Rub. Mix well.
Remove chicken from marinade, letting excess drip off.
Dredge each piece in seasoned flour, pressing it in to coat well.
Place coated chicken on a wire rack over a baking sheet. Let rest 15–20 minutes to set the coating.
Dredge chicken in the seasoned flour again, pressing firmly for a thick crust. Shake off excess.
Heat oil in a deep pot to 325°F.
Fry chicken in batches without crowding, about 12–15 minutes for thighs and 10–12 minutes for drumsticks, until golden brown and internal temperature reaches 165°F.
Transfer to a clean wire rack to drain and keep crispy.