In a bowl, combine the buttermilk, garlic powder, onion powder, paprika, salt, and pepper. Mix well.
- Place the chicken breasts in the buttermilk mixture, making sure they are fully submerged. Cover and refrigerate for at least 2 hours (overnight for best results).
- In a separate shallow dish, combine the flour, baking powder, cayenne pepper (if using), salt, and pepper. Mix well.
- Heat about 1-2 inches of vegetable oil in a large skillet over medium-high heat.
- Remove the chicken from the buttermilk and dredge each piece in the flour mixture, pressing gently to ensure a thick coating.
- Carefully place the coated chicken in the hot oil and fry for 5-6 minutes per side, or until golden brown and crispy. The internal temperature should reach 165°F (75°C) to ensure the chicken is cooked through.
- Once the chicken is cooked, transfer it to a plate lined with paper towels to drain any excess oil.
- Toast the sandwich buns lightly in the skillet or oven until golden brown.
- To assemble the sandwich, spread mayonnaise on the bottom half of each bun. Add a layer of fresh lettuce and a few slices of pickles.
- Place the fried chicken breast on top, then top with the other half of the bun.
- Serve immediately and enjoy!