Combine buttermilk, hot pepper sauce, and 1 teaspoon of salt in a 2-gallon self-sealing plastic bag; add chicken pieces, turning to coat.
Seal the bag, pressing out the excess air.
Place bag in a bowl and refrigerate 2 to 24 hours to marinate, turning bag over once.
Combine flour, baking powder, pepper, paprika, and remaining 2 teaspoons salt in a shallow dish until well mixed.
Remove chicken, a few pieces at a time, from the buttermilk mixture shaking off excess.
Add chicken to the flour mixture, turning to coat well.
Place chicken on a wire rack, set over waxed paper without pieces touching.
Repeat with remaining chicken, using a 2nd rack if necessary; let stand 15 minutes to set coating; discard buttermilk mixture.
Preheat oven to 250 degrees.
Line 2 large cookie sheets with paper towels.
Place 1/2 inch oil in two large frying pans (electric frying pans are great for frying chicken); heat over med heat until hot.
Place chicken pieces into hot oil being careful not to crowd or let pieces touch.
Cover skillets and cook until chicken is light golden brown on the bottoms, about 4 to 5 minutes.
Turn pieces over and cook, covered, 8 to 10 minutes longer for white meat, 13 to 15 minutes for dark meat, turning every 4 to 5 minutes or until well browned on all sides and juices run clear when the thickest part is pierced with a knife tip.
Transfer chicken to the paper towel lined cookie sheets in the oven to keep warm.