Begin by mixing together in a small bowl or large measuring cup the buttermilk, garlic powder, Italian seasonings, red pepper, and some salt.
Next pour the buttermilk mixture into a large zip-top plastic bag or a large baking dish and add the chicken pieces. Fully coat the chicken with the buttermilk mixture. Seal/cover and refrigerate for at least 2 hours or up to overnight. Turn the chicken occasionally in the marinade. When ready to cook, remove the chicken from the refrigerator 30 minutes ahead of time.
To grill, heat the grill to medium-low. Once heated place the marinated chicken on grill, cover and cook, turning occasionally, until golden brown and cooked through, about 30 to 40 minutes. (Discard the unused marinade.)
To bake, preheat the oven to 450-degrees F. Place the marinated chicken in a single layer in an oven safe skillet or baking pan. Bake until done, about 30 minutes. Be sure to check for doneness.