Bring a large pot of salted water to a boil. Add the pasta and cook for 2 minutes less than package directions.
Heat a large skillet over medium-high heat. Add the oil and chopped prosciutto. Cook, stirring constantly until crisp and golden brown, mabout 4 minutes. Using a slotted spoon, remove the prosciutto to a paper towel lined plate.
Add unsalted butter to the same skillet. Add pear, salt, and pepper, and cook, stirring often, about 1 minute. Transfer the pasta to the skillet. Add the mascarpone cheese. Toss until the mascarpone has warmed and coated the pasta, adding splashes of pasta water as needed to help thin the sauce.
Taste and add salt and pepper as desired. Divide into plates and garnish with parsley, prosciutto, and parmesan cheese.