Set each breast in between two layers of plastic wrap and flatten to 3/4 inch thickness by using a mallet or rolling pin. Soak chicken in 1 cup buttermilk for at least 30 minutes.
In a shallow dish, combine remaining ingredients. Shake excess buttermilk off each piece of chicken and coat in the bread mixture.
1 cup panko bread crumbs, 1 cup parmesan cheese, 1 teaspoon garlic powder, 1 teaspoon paprika, 1 teaspoon dried thyme
Lay in a single layer on a baking sheet and bake in preheated 400°F oven for about 20 minutes or until the internal temperature reaches 165°F.