Bring a large pot of salted water to a boil, add the asparagus and cook until tender.
Using tongs, transfer the asparagus to a bowl, and then drain well in a colander.
Cut off and reserve the asparagus tips: roughly chop the stems.
In a blender, puree the asparagus stems, ricotta and a dash of salt, until smooth. Taste and add more salt if desired.
Return water to a boil and cook the pasta until al dente. Reserve serving ½ cup of the pasta cooking water, drain pasta and transfer to a large serving bowl.
Immediately toss with ricotta mixture, and then add Parmigiano and prosciutto.
Toss to combine. Moisten with pasta cooking liquid if desired. Garnish with reserved asparagus tips and serve immediately.