In a large bowl, combine the buttermilk with the salt, black pepper and cayenne. Add the chicken and turn to coat. Let stand at room temperature for 2 hours or refrigerate for 4 hours.

In a large bowl, whisk the flour with the onion powder, garlic powder, cayenne, salt and black pepper. Whisk in the beer to make a thin batter.

Drain the chicken and thoroughly pat thoroughly dry with paper towels. Transfer the chicken to the batter, turning to coat.

In a large, deep skillet, heat 1 inch of oil to 350 degrees . Set a rack over a baking sheet and line the rack with paper towels. Lift the chicken from the bowl, letting the excess batter drip back into the bowl. Fry the chicken in batches at 315 degrees , turning once, until golden and an instant-read thermometer inserted in the thickest part registers 160 degrees ; about 18 minutes for wings and 20 minutes for thighs, breasts and drumsticks. Transfer the fried chicken to the rack and let stand for 5 minutes before serving.

The fried chicken can be kept at room temperature for up to 4 hours.