Mix the artichoke hearts, green onions, garlic, cream cheese, mayonnaise, sour cream, mozzarella cheese, and Parmesan cheese, reserving some of the cheese for topping.
Hollow 1/2 inch out of the center of both halves of the bread.
Spread the mixture into the hole in the bread halves and top with the reserved cheese.
Cover with foil and bake in a preheated oven set at 350 degrees for 20 minutes.
Remove the foil and continue to bake until the cheese is melted and golden brown.