1/3 cup reduced-fat buttermilk
Olive oil spray
1 oz fat-free herb-seasoned croutons
Place the chicken breasts in a medium resealable plastic bag. Pour the buttermilk over them and seal the bag. Let them soak 6 hours, or overnight, turning once or twice.
Preheat the oven to 450°F. Lightly mist a small non-stick baking pan or sheet with olive oil spray. Add the croutons to another resealable plastic bag. Pound them into very fine crumbs with the flat side of a meat mallet. Transfer the crumbs to a medium shallow bowl. Remove 1 breast from the bag and let any excess buttermilk drip off. Dip it into the crouton crumbs, covering the breast completely. Place the breaded breast on the prepared baking sheet. Repeat with the second breast. If crumbs remain, press them into the tops of the chicken breasts.
Lightly spray the chicken breasts with olive oil. Bake for 5 minutes. Flip them, being careful not to remove the coating. Lightly spray with olive oil and continue to bake for another 3 to 5 minutes, or until the coating is crisp and the chicken is no longer pink inside.