Bring 6-quarts of water to a boil and add 2 tablespoons salt. Place the cauliflower florets into the boiling water. Cook until the cauliflower is slightly resistant to a fork, 7 to 8 minutes. Drain, reserving the cooking water. Set aside. Pour 1/4 cup of the cauliflower cooking water into a small bowl. Add the saffron and let it dissolve. Set aside.
In a 12 to 14-inch saute pan over high heat, heat 4 tablespoons olive oil until almost smoking. Add the garlic, florets and anchovies, and saute for 2 minutes. Add the pine nuts and saute for 1 minute. Remove from the heat and set aside.
Bring the cauliflower water back to a boil and add the ziti. Cook until parboiled, about half-done. Drain well.
Preheat the oven to 375 degrees F.
Pour the ziti into a large, deep, ovenproof casserole. Stir in the cauliflower mixture and 1/2 of the cheese. Sprinkle with the saffron water and mix gently. Sprinkle with the remaining cheese. Crumble the bread crumbs on top and drizzle with the remaining 1 tablespoon of olive oil. Bake for 15 minutes. Serve immediately.