Pancetta (Italian cured bacon) adds salty flavor to this pasta dish; its richness is balanced by crisp-tender green beans and aromatic basil.
In a large pot of boiling salted water, cook pasta until al dente. Reserve 1 cup pasta water; drain pasta, and return to pot.
Meanwhile, cook pancetta in a large skillet over medium until browned and crisp, 10 to 12 minutes. Using a slotted spoon, transfer to a paper-towel-lined plate to drain. Pour off all but 1 tablespoon fat from skillet (reserve skillet).
Add green beans to skillet; season with salt and pepper. Cover, and cook until beans are crisp-tender, 5 to 7 minutes; transfer to pot with pasta. Add pancetta, cup Parmesan, and enough reserved pasta water to create a thin sauce that coats pasta. Top with basil and remaining cup Parmesan; serve immediately.