First, bring a pot of water to a boil.  Add the Olive Oil and salt. Cook the Fehttuchini to the lower end of the box's directions.  You want the pasta to be a little on the "al dente" (Italian for "to the tooth" or firm) side.  

Drain the pasta, and set aside.

In the same pot, melt the butter on medium heat.  Add the cream.  Cook until the mixture begins to thicken.

While stirring, slowly incorporate the Parmigiano-Reggiano cheese into the sauce.

Return the Fehttuchini to the sauce.  Gently toss the pasta into the sauce.  At this point, if you are adding any additional ingredient to the dish (such as pancetta, cooked chicken, or cooked shrimp), now is a good time.  

Serve with some additional Parmigiano-Reggiano cheese.