1. Combine buttermilk, 1/4 cup salt, and Tabasco sauce, if using, in a large, airtight container. Add chicken pieces, turning to coat in the liquid. Cover, and refrigerate at least 2 hours or overnight.
2. Preheat oven to 200 degrees F. Combine flour, remaining 5 teaspoons salt, black and cayenne peppers, and baking powder in a brown paper bag. Shake vigorously.
3. One at a time, place chicken pieces in the bag, and shake to coat. Place coated pieces on a clean plate or tray. Heat vegetable shortening (and bacon drippings, if using) in two 10-inch cast-iron skillets over medium-low heat. Using a frying thermometer to measure temperature, bring shortening to 375 degrees F; it should be at a medium, not a rolling, boil. Use tongs to place thighs and drumsticks in skillets. Fry until coating is dark golden on bottom, 10 to 14 minutes; then, using tongs, turn chicken over. Cook until coating is dark golden, another 10 to 14 minutes. An instant-read thermometer inserted into a thigh should register 170 degrees F. Drain on brown paper bags or several layered paper towels. Transfer cooked pieces to baking sheets, and place in the oven to keep warm while frying remaining chicken. Using a slotted spoon, remove any bits of coating left in skillets, and discard. Place breasts and wings in skillets. Cook 10 to 14 minutes on each side. Drain on brown paper bags. Remove dark meat from oven, and serve.

Yield: 8 servings