Pat the drumsticks dry with paper towels. This helps the coating stick and the skin get extra crisp.
In a bowl, whisk together buttermilk, hot sauce, salt, pepper, paprika, garlic powder, and onion powder. Add the drumsticks and turn to coat. Cover and refrigerate for 1 hour, or up to overnight for more flavor.
In a shallow dish, place the flour. Remove each drumstick from the buttermilk bath, letting excess drip off, then dredge in the flour until evenly coated. For an extra-crispy crust, press the flour onto the surface gently and shake off the excess.
Heat the oil in a heavy pot or skillet to 350°F (175°C). Use a thermometer to keep the temperature steady. If you don’t have one, drop a pinch of flour into the oil; it should sizzle immediately.
Fry the drumsticks in batches, turning once, until golden brown and cooked through, about 12-14 minutes per batch depending on size. The internal temperature should reach 165°F (74°C).
Remove the fried chicken to a rack set over a baking sheet to drain excess oil. Let rest for a few minutes before serving to keep the crust crisp.