In a large pot of lightly salted boiling water, cook the orchiette according to package directions.
Before draining the pasta, dip a measuring cup into the cooking water and measure out ½ cup of the water; set aside. Drain the pasta and set aside.
Meanwhile, in a large skillet over medium-high heat, heat the olive oil. Add the Italian sausage and cook, breaking into a crumble with a spoon, until no longer pink, about 7 minutes.
Add the cream, tarragon, and salt, and bring to a boil. Reduce heat to medium-low. Add spinach and cook, stirring well, until wilted.
Add the orchiette and reserved cooking water, stirring well to coat pasta with sauce. Add the Parmesan cheese, stirring well to mix.