Bring a large pot of generously salted water to a rolling boil for the bucatini.

In a large skillet over medium heat, add the diced guanciale and chili flakes. Cook, stirring occasionally, until the guanciale is crispy and its fat has rendered, about 5-7 minutes.

Pour in the white wine, scraping up any browned bits from the bottom. Let it bubble until the alcohol smell dissipates and the wine has almost completely evaporated, about 2 minutes.

Add the hand-crushed tomatoes along with their juices. Season with a pinch of salt. Lower the heat and simmer gently, stirring occasionally, until the sauce thickens slightly, 10-12 minutes.

Meanwhile, cook the bucatini in the boiling water for 1 minute less than the package directions for al dente.

Drain the pasta, reserving about 1 cup of the starchy pasta water. Transfer the bucatini directly to the skillet with the sauce. Toss vigorously over medium heat, adding splashes of reserved pasta water as needed, until the sauce clings to every strand and looks glossy.

Remove the skillet from the heat. Sprinkle the grated Pecorino Romano and a generous amount of black pepper over the pasta. Toss again until the cheese melts and coats the pasta.

Divide among warm bowls, top with extra pecorino and black pepper, and serve at once.