Preheat oven to 250 degrees F (120 degrees C). Mix 1 1/2 cups Parmesan cheese, cream cheese, artichoke hearts, mayonnaise, salt, and pepper together in a stand mixer; pour into an 8-inch square baking dish. Sprinkle 1 tablespoon Parmesan cheese over the top of the mixture. Bake in preheated oven until bubbly and golden brown on top, about 25 minutes.