Place chicken pieces in a large bowl and cover with buttermilk. Refrigerate for at least 2 hours or overnight.
In a shallow dish, combine flour, seasoned salt, black pepper, paprika, garlic powder, and cayenne pepper. Mix well.
Heat vegetable oil in a large, deep skillet or Dutch oven to 350°F.
Remove chicken from buttermilk, allowing excess to drip off. Dredge each piece thoroughly in the seasoned flour mixture.
Dip the floured chicken back into the buttermilk briefly, then dredge again in the flour mixture for a thick coating.
Carefully place chicken pieces in the hot oil, skin-side down, without crowding. Fry in batches if necessary.
Cook for 12-15 minutes per side until golden brown and internal temperature reaches 165°F.
Remove chicken to a wire rack set over a baking sheet to drain. Let rest for 5 minutes before serving.