Place chicken cutlets in a bowl and pour buttermilk over top. Let sit for at least 10 minutes (or up to 2 hours in the fridge for extra tenderness).
In a shallow dish, whisk together flour, cornstarch, garlic powder, paprika, salt, and pepper.
Remove chicken from buttermilk, letting excess drip off, then dredge each piece in the flour mixture. Press lightly so the coating sticks well. Transfer to a plate until ready to fry.
Heat about ½ inch of oil in a large skillet over medium heat until hot (about 350°F).
Carefully add chicken to the pan in a single layer. Cook for 4–5 minutes per side, until golden brown and cooked through (internal temperature reaches 165°F).
Transfer to a wire rack set over a baking sheet. Let rest for 5 minutes before serving.
Serve immediately for best texture, with your favorite sides or dipping sauces.