In a heavy-bottomed saucepan, bring 6-quarts of water to a boil and add 2 tablespoons of salt. Divide the cauliflower into florets. Blancy the cauliflower in the boiling water until half-cooked, about 10 minutes. Drain the cauliflower, reserving the cooking water for the ziti. Set the par-cooked cauliflower aside.
Chop and mince anchovies.
Dissolve the saffron strands in a few tablespoons of warm water.
Toss fish, tomato and sliced garlic. In a 3-quart saucepan, heat the olive oil over medium heat in a saute pan. Add the raisins, pine nuts, saffron tea, and the anchovies. Using a wooden stir and continue cooking over medium heat until the anchovies dissolve, about 7 minutes. Add half of the cooked cauliflower and season, to taste, with salt and pepper. Cover and let cook until the cauliflower is tender, about 5 minutes.
Lower heat to low and allow to cook, uncovered, while you prepare the ziti. Return the cauliflower water to a boil. Add the ziti and cook halfway, about 5 minutes. Drain the pasta and add to the sauce. Add the remaining cauliflower, cover and let stew over medium-low heat until the pasta and cauliflower are cooked through, about 5 minutes. Toss with extra-virgin olive oil, chopped parsley and caciocavallo. Season with salt and pepper and serve immediately.