Pound the chicken breasts slightly so they cook evenly.
Marinate chicken in buttermilk for at least 1 hour or overnight for best results.
In a large bowl, mix together the flour, garlic powder, paprika, cayenne, salt, and pepper.
Heat vegetable oil in a heavy skillet over medium-high heat until hot enough for frying.
Remove chicken from buttermilk, dredge each piece in the seasoned flour, and shake off excess.
Fry the chicken in batches, about 6 to 8 minutes per side, until golden brown and cooked through.
Place fried chicken on a wire rack to drain and keep it crispy before serving.