Preheat oven to 425F (220C). Line a large baking sheet with aluminum foil. Place a wire cooling rack on top, and spray wire rack with cooking spray. Set aside.
In a shallow bowl whisk together melted butter, garlic powder, and salt.
In a separate shallow bowl, combine cracker crumbs and cheeses.
Dip chicken in butter mixture, then coat with crumbs.
Place chicken on the prepared rack on the baking sheet. Lightly spray chicken with cooking spray or oil (this will help the crust brown).
Bake for 15-20 minutes, turning once, until chicken is no longer pink inside and the coating is golden and crispy.