Mix the buttermilk, garlic powder, garlic salt, and ground black pepper in a large container.
Cover the chicken pieces in the buttermilk mixture and refrigerate overnight.
Combine flour, paprika, salt, and pepper in a large plastic bag.
Drain the chicken pieces from the buttermilk mixture.
Place a few pieces of chicken at a time into the bag with seasoned flour.
Seal the bag and shake to coat each piece evenly.
Heat vegetable oil in a large skillet until hot but not smoking.
Fry the chicken in batches until golden brown and cooked through, about 15-20 minutes per batch.
Remove the chicken using tongs and rest on a wire rack for about 5 minutes before serving.