Bring a large pot of salted water to a boil. Add the pasta and cook as the label directs. Reserve 1 cup of the cooking water; drain the pasta.
Meanwhile, cook the bacon in a large skillet over medium heat, stirring occasionally, until crisp, about 8 minutes. Remove with a slotted spoon and drain on paper towels; pour off all but 1 tablespoon of the drippings from the skillet.
Add the leeks to the drippings in the skillet. Season with 1/2 teaspoon each salt and pepper and cook, stirring occasionally, until soft, about 3 minutes. Add the heavy cream and cook until it begins to thicken, about 2 minutes.
Add the pasta to the skillet along with the parmesan, half of the bacon and 1/2 teaspoon pepper; toss to coat, adding enough of the reserved pasta cooking water to loosen. To serve, top with the remaining bacon, more parmesan and parsley.
Photograph by Justin Walker
Courtesy of Food Network Magazine