Combine chicken pieces, buttermilk, hot sauce, salt, and pepper in a large resealable plastic bag. Refrigerate 2 hours or up to overnight.
Drain; season with salt.
Dredge in flour, shaking off the excess.
Fry in batches, turning occasionally, in 1 inch of canola oil over medium heat (360° F on a deep-fry thermometer), until cooked through, 10 to 15 min.
* Total Time includes marinating