Heat oven to 375º. Place bread, cut sides up, on ungreased cookie sheet. Bake 10 minutes.
Mix 1/2 cup of the mozzarella cheese, the Parmesan cheese, rosemary, mayonnaise and artichokes; spread on bread. Sprinkle with remaining 1/2 cup mozzarella cheese. Bake 15 to 20 minutes or until cheese is melted.