- Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper or a silicone baking mat. 
- In a large bowl, combine buttermilk, garlic powder, onion powder, paprika, salt, and black pepper. Add the chicken pieces, ensuring they are well-coated. Cover and refrigerate for at least 1 hour, or overnight for best results. 
- In another bowl, mix together the flour, cornmeal, dried thyme, and baking powder. 
- Remove the chicken from the buttermilk mixture, allowing excess to drip off. Dredge each piece in the flour-cornmeal mixture, pressing lightly to adhere. 
- Place the coated chicken pieces on the prepared baking sheet. Lightly spray or drizzle with cooking spray or olive oil to help them crisp up. 
- Bake in the preheated oven for 35-45 minutes, or until the chicken is golden brown and reaches an internal temperature of 165°F (74°C). Flip the chicken halfway through for even cooking. 
- Let the chicken rest for 5 minutes before serving.