Bring 6 quarts of water to a boil in a large pot and add 2 tablespoons salt.

Meanwhile, in a 10- to 12-inch sauté pan, heat the olive oil over low heat. Add the guanciale and cook slowly until the guanciale has rendered its fat and is crisp and golden brown, about 10 minutes. Add the onion and garlic and cook gently until golden brown, about 5 minutes longer. Remove from the heat.

Cook the Barilla farfalle in the boiling water for 1 minute less than the package instructions indicate; drain, reserving 4 tablespoons cooking water. Add the pasta to the pan with the reserved cooking water. Add the truffle paste, guanciale and the grated cheese; mix well and toss over high heat for one minute. Add the arugula and toss for about 30 more seconds, until just wilted.

Divide among four warmed pasta bowls and serve with additional cheese on the side.

Bring 6 quarts of water to a boil and add 2 tablespoons of salt. In a 12- to 14-inch sauté pan, heat 2 tablespoons of the olive oil over medium heat. Add the onion, garlic and anchovies. Cook over medium heat, stirring occasionally, until the onion and garlic are softened and the anchovies have begun to break up.

Turn the heat up to high and add the squash cubes. Cook over high heat for 5 minutes or until the cubes are tender and browned at the edges. Season with the salt and pepper and remove from the heat.

Cook the Barilla fettuccine in the boiling water for 1 minute less than according to the package directions. While the pasta is cooking, warm the squash mixture. Drain the pasta and add it to the pan with the squash. Add the parsley and remaining 2 tablespoons of olive oil and toss over high heat for 1 minute.

Divide the pasta and squash evenly among four warmed pasta bowls, top with bread crumbs and serve immediately.