Begin by soaking your bone-in, skin-on chicken thighs in buttermilk for at least 30 minutes, or ideally overnight for maximum tenderness.

While the chicken marinates, preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or place a wire rack on top of it.

In a medium bowl, mix together flour, garlic powder, onion powder, thyme, salt, and black pepper. Pat each marinated chicken thigh dry and thoroughly coat them in the seasoning mix.

Place the seasoned chicken thighs skin-side up on the prepared baking sheet or wire rack. Bake in the preheated oven for 30-35 minutes, until the skin is golden brown and crispy.

Once baked, remove the chicken thighs from the oven and let them rest for about 5 minutes before serving.