Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a shallow bowl, combine the buttermilk, garlic powder, paprika, salt, and pepper.
Place the chicken breast between two sheets of plastic wrap and gently pound it to ensure even thickness.
Submerge the chicken in the buttermilk mixture, coating it well. Allow it to marinate for at least 30 minutes in the refrigerator.
In a separate shallow dish, spread out the panko breadcrumbs.
Remove the chicken from the marinade, letting the excess drip off, and gently press it into the breadcrumbs to coat both sides evenly.
Place the coated chicken on the prepared baking sheet and lightly spray the top with olive oil spray for extra crispiness.
Bake in the preheated oven for 20-25 minutes or until the chicken is fully cooked and the coating is crispy, turning once halfway through if desired.
Remove from the oven, let rest for a few minutes, and serve warm.