Pound the chicken breasts lightly and trim any extra fat off.

In a small bowl, stir together the Cajun seasoning, pepper, garlic powder, onion powder and sugar.

Add 1 tablespoon of the seasoning mix to the buttermilk and stir to combine. Pour the buttermilk mixture over the chicken. Let the chicken marinate for at least 1 hour up to overnight.

When you are ready to start cooking, combine the remaining seasoning mix with the flour and stir to combine.

Add 3 to 4 tablespoons of the buttermilk marinade into the flour mixture, mixing gently; leave some chunky flour pieces for crispiness.

Dredge the chicken in the flour mixture and dip back into the buttermilk. Dredge again in the flour mixture, pressing the chunky pieces into the chicken.

Heat 4 cups vegetable oil in a large heavy pot over medium-high heat until flour sizzles upon contact.

Fry 2 pieces of chicken at a time for 5-6 minutes on each side, ensuring internal temperature reaches 165°F.

Remove cooked chicken and drain on a cooling rack. Repeat with remaining chicken.

Assemble sandwiches by placing the fried chicken on toasted brioche buns with mayonnaise and pickles, if desired.