Squeeze out excess juices from spinach and drain artichoke hearts. Dice artichoke hearts into smaller pieces.
In a mixing bowl, combine cream cheese, Mozzarella cheese, Parmesan cheese, pressed garlic, sour cream, mayo, parsley, salt, and pepper. Mix very well until all incorporated.
Mix in the spinach and chopped artichoke hearts. Transfer into a lightly greased baking dish.
Top off with a shredded Mozzarella cheese and grated Parmesan.
Double The Recipe: You can easily double this recipe and use a 9x13 baking dish. You don't need to adjust the bake time much, in the larger casserole dish, it will take about 20-22 minutes to cook.
Using Fresh Spinach: Get a 10 oz package of baby spinach, chop it, and cook it down covered with a lid, over medium-low heat. Make sure to squeeze the excess liquid from the cooked spinach before adding to the dip.