1 large head of cauliflower (28 to 30 ounces), trimmed, cut into 1-inch florets
8 T. extra-virgin olive oil, divided
1 pound orecchiette (little ear-shaped pasta) or medium-size shell pasta
1 1/2 C. 1/3-inch cubes crusty country-style bread
3 medium zucchini, trimmed, cut into 1/3-inch cubes (about 3 C.)
3 large garlic cloves, chopped
7 anchovy fillets, finely chopped
1/2 C. chopped fresh Italian parsley, divided
1/3 C. (packed) freshly grated Parmesan cheese plus additional for serving
2 T. freshly grated Pecorino Romano cheese

Preheat oven to 425 degrees F. Toss cauliflower florets with 1 T. olive oil in large bowl to coat. Sprinkle with salt and pepper and spread in single layer on large rimmed baking sheet. Roast until cauliflower florets are tender and beginning to brown in spots, stirring occasionally, about 25 minutes. Cool to room temperature. Can be made 1 day ahead. Cover and chill. Cook pasta in large pot of boiling generously salted water until just tender but still firm to bite, stirring occasionally. Drain pasta, reserving 1 1/3 C. pasta cooking liquid. Set pasta and cooking liquid aside separately. Meanwhile, heat 2 T. olive oil in large deep nonstick skillet or large pot over medium-high heat. Add bread cubes and saute until golden brown and crisp, 3 to 4 minutes. Transfer to small bowl and cool. Reserve skillet or pot. Add 2 T. olive oil to same skillet or pot and heat over medium-high heat. Add zucchini and garlic and saute until zucchini is golden brown and crisp-tender, 3 to 4 minutes. Add cauliflower and anchovies and saute until heated through, 3 to 4 minutes. Season to taste with salt and freshly ground black pepper. Add drained pasta, reserved 1 1/3 C. pasta cooking liquid, remaining 3 T. olive oil, 1/3 C. parsley, 1/3 C. Parmesan, and Pecorino Romano cheese and toss to coat. Season pasta to taste with salt and freshly ground black pepper. Divide pasta among 6 bowls; sprinkle with fried croutons, remaining parsley, and additional Parmesan cheese and serve.