Preheat oven to 400 degrees F.
Defrost spinach 6 minutes on high and wring the spinach dry in a kitchen towel.
Crust bread in oven for 5 or 6 minutes. Remove and split bread in half from end to end as if it were a large sandwich roll.
Turn broiler on. If your broiler is too small to place ciabatta breads under it, you can melt the cheese in oven as well, see below, it simply browns faster under broiler.
Drizzle hot bread with extra-virgin olive oil. Mix ricotta, garlic, parsley and grated cheese. Spread the mixture evenly over the bread halves then dot with the defrosted chopped spinach. Evenly distribute the sliced artichokes, season the breads with salt and pepper and top with an even layer mozzarella cheese. Melt and brown the cheese under the broiler 3 minutes, 1 rack down from the top of the oven. If you are using the oven rather than broiler, the cheese will take 6 or 7 minutes to brown. Cut into bread into wedges and serve. If desired, serve with Dipping Sauce.
Heat a small pot over medium heat. Add extra-virgin olive oil, garlic, pepper flakes and anchovy paste. Cook 2 minutes. Add parsley, tomatoes, salt and pepper. Stir sauce, bring to a bubble and simmer 5 minutes over low heat then place in small bowl and serve.