Preheat the oven to 375 degrees F (190 degrees C). Spray a baking dish with cooking spray.

Mix together artichoke hearts, Parmesan cheese, mayonnaise, and garlic pepper in a medium bowl.

Place chicken in the prepared baking dish. Cover evenly with artichoke mixture.

Bake, uncovered, in the preheated oven until browned in places, chicken is no longer pink in the center, and juices run clear, about 30 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).