Pound chicken breasts in between two pieces of parchment paper or plastic wrap. Cut each chicken breast in half crosswise to make 2 small pieces of chicken about the same size as the bun (see video below).
In a large bowl, buttermilk, paprika, garlic powder, salt & black pepper. Add the chicken to the mix and place in the fridge to marinate up to 24 hours or use right away.
To Cook Chicken
Heat oil in a large heavy-duty skillet or pot on medium temperature or until the temperature reaches 350F.
In a medium shallow bowl, whisk the flour, cornstarch, and spices. Drizzle 2-3 tablespoons of the buttermilk batter into the flour mixture and mix it through with a fork.Working with 1 piece at a time, dredge chicken the flour mixture and press flour on the top chicken to form a thick crust. Transfer chicken to hot oil and fry for 3-5 minutes per side or until the outside is crispy and golden and the internal temperature reaches 165F.
Melt 1 tablespoon butter in a large saucepan and toast buns face down until golden and crisp. Whisk all the ingredients for the mayo in a small bowl and spread a generous layer of mayo on each bun. Top with pickles and chicken. Enjoy hot!