
Preheat oven to 350 degrees F (175 degrees C).
Stir mayonnaise, garlic, rosemary, salt, and black pepper together in a bowl. Place chicken pieces into a 9x13-inch baking dish, spread mayonnaise mixture over chicken, and top with Parmesan cheese.
Bake until the juices run clear, chicken is no longer pink in the middle, and an instant-read meat thermometer inserted into the thickest chicken piece reads at least 160 degrees F (70 degrees C), about 1 hour and 10 minutes.