Remove any excess liquid from spinach and add to the pan. Rinse and drain the artichoke hearts and add to the pan. Give the artichoke a rough chop before adding to the pan or simply break them up with a spatula while sautéing. Cook for 3-4 minutes until spinach and artichoke are heated through. Once done, turn off burner and set aside.
In a large bowl, add sour cream, mayo, cream cheese, parmesan, mozzarella, salt and cayenne pepper. Mix to combine with a rubber spatula and set aside.