In a large bowl, combine buttermilk, garlic powder, onion powder, smoked paprika, thyme, salt, and black pepper.
Add the rabbit thighs to the marinade, ensuring they are fully coated. Cover and refrigerate for at least 2 hours, preferably overnight.
In a separate bowl, mix the flour and cornmeal.
Heat oil in a deep skillet or fryer to 350°F (175°C).
Remove rabbit thighs from the marinade, allowing excess buttermilk to drip off.
Dredge each thigh in the flour-cornmeal mixture, pressing lightly to adhere coating.
Carefully place thighs in the hot oil, frying in batches to avoid overcrowding.
Fry for 8-10 minutes, or until golden brown and internal temperature reaches 165°F (74°C).
Use a slotted spoon to transfer thighs to a paper towel-lined plate to drain excess oil.
Serve hot with your favorite dipping sauce or a squeeze of fresh lemon.