Bring a large saucepan of salted water to a boil. Add the spaghetti and cook until al dente according to package instructions.

While the spaghetti cooks, heat the olive oil in a large frying pan over medium heat. Add the sliced garlic and capers, and cook gently for 1-2 minutes, until fragrant. Add the anchovy fillets and stir until they dissolve into the oil.

Stir in the halved plum tomatoes and add 6 tablespoons of the hot pasta cooking water. Let the mixture simmer over medium heat for about 5 minutes to meld the flavors.

Drain the cooked spaghetti and, using tongs, transfer it directly to the frying pan. Toss well to coat the pasta in the sauce.

Stir in the grated Parmesan, Italian Volcano lemon juice, chopped parsley, butter, and a generous grinding of black pepper. Mix everything thoroughly until the butter melts and the sauce evenly coats the pasta.