In a Large pot bring water to a boil on high heat, adding a generous amount of salt. Add the tagliatelle, stirring occasionally so as not to stick and cook 2’ less than package instructions. Reserve 1 cup of cooking water.

In the meantime, in a large pan over medium heat the olive oil and add the prosciutto. Cook for 2-3’ until a bit crispy. Remove from the pan to a plate with a paper towel to absorb the extra oil.

In the same pan add the butter over low heat and once melted and bubbly add the mascarpone. Stir and season with the salt and pepper. Pour the lemon juice and half of the parmesan cheese, stir once again and add some of the reserved pasta water to create a nice cream of the consistency required.

Drain the tagliatelle and return to the pan with the sauce while tossing for a minute. Then add half of the prosciutto and toss a bit more.

Serve in a flat dish, top with the remaining prosciutto and sprinkle the remaining parmesan cheese.