Lightly pound chicken just enough to even it out; do not pound it thin.
Place the chicken in a large bowl and season with salt and pepper; set aside.
In a separate bowl, combine garlic, yogurt, and thyme; mix until combined.
Pour the yogurt mixture over the chicken; mix around until the chicken is thoroughly coated.
Cover with plastic wrap and refrigerate for 4 to 6 hours.
Preheat the oven to 375˚F.
Grease a baking dish/pan with cooking spray.
Remove the chicken from the bowl and shake off any excess; discard the yogurt mixture.
Transfer the chicken breasts to the baking pan.
Sprinkle panko bread crumbs over the chicken breasts.
Bake for 40 to 45 minutes, or until chicken is done. Use an instant-read meat thermometer to check for doneness; chicken is cooked through when its internal temperature registers at 165˚F.
Remove from oven and let stand for 5 to 8 minutes.
Serve.