In a large bowl, combine buttermilk, salt, pepper, garlic powder, and paprika. Add chicken pieces and coat well. Cover and refrigerate for at least 2 hours or overnight.
Preheat oven to 400°F. Line a baking sheet with parchment paper.
In a shallow dish, mix flour with garlic powder, paprika, salt, and pepper.
Remove chicken from buttermilk, letting excess drip off. Dredge each piece in the seasoned flour mixture.
Place chicken on the prepared baking sheet. Drizzle or spray with oil.
Bake for 35-45 minutes, flipping halfway through, until golden brown and internal temperature reaches 165°F.
Let rest for 5 minutes before serving.