01 - In a large bowl, whisk together buttermilk, salt, black pepper, garlic powder, and smoked paprika. Add chicken pieces, turning to coat thoroughly. Cover and refrigerate for at least 30 minutes, preferably overnight for enhanced flavor.
02 - Preheat oven to 425°F. Line a baking sheet with parchment paper and position a wire rack on top.
03 - In a shallow dish, combine panko breadcrumbs, all-purpose flour, onion powder, dried thyme, cayenne pepper if using, salt, and black pepper.
04 - Remove chicken from marinade allowing excess to drip off. Dredge each piece in the breadcrumb mixture, pressing firmly to ensure an even coating.
05 - Place chicken pieces skin-side up on the wire rack set over the baking sheet. Drizzle olive oil evenly over the coated chicken to promote crispiness.
06 - Bake in preheated oven for 35 to 40 minutes until skin is golden brown and crisp, and the internal temperature reaches 165°F. Remove and let rest for 5 minutes before serving.