Place the chicken breasts between two sheets of plastic wrap and gently pound them to an even thickness, about 1/2 inch.
In a shallow dish, pour the buttermilk. Dip each chicken breast into the buttermilk, allowing any excess to drip off.
Generously coat each chicken breast with the blackened seasoning mixture, pressing it onto the chicken to adhere.
In a large skillet, heat about 1/2 inch of vegetable oil over medium-high heat until it reaches 350°F (175°C).
Carefully add the chicken breasts to the hot oil. Fry for about 6-8 minutes per side or until they are fully cooked and have a blackened appearance. The internal temperature should reach 165°F (74°C).
Remove the chicken from the skillet and place them on a paper towel-lined plate to drain any excess oil.