Heat oven to 400 degrees. Line cookie sheet with foil; spray with cooking spray. Sprinkle chicken with salt and pepper to taste.
In shallow dish, mix Italian dressing mix and the garlic powder. In another shallow dish, Parmesan cheese. Dip chicken into Parmesan cheese to coat. Place on cookie sheet.
Bake 12 to 15 minutes, turning once, until juice of chicken is clear when center of thickest part is cut (at least 165 degrees F) and coating is golden brown.