Bring a large pot of well-salted water to a boil over high heat.
Meanwhile, in a large sauté pan, heat the olive oil over medium heat. Add the onion and cook until softened, about 5 minutes. Add the garlic and cook for 1 minute. Add the sausage and cook, breaking it into bite-size pieces with a spoon, until just cooked through, 6 to 8 minutes. Spoon off the fat if it's excessive. Add the wine, increase the heat to medium high, and cook, scraping up any browned bits in the pan, until most of the wine is evaporated, 3 to 5 minutes. Stir in the olives and sun-dried tomatoes and cook for 2 minutes.
Add the cream, increase the heat to high, bring to a boil, and cook, stirring occasionally, until the cream thickens slightly, 2 to 5 minutes. Stir in 2 Tbs. of the parsley and 2 Tbs. of the Parmigiano. Keep the sauce warm over low heat.
Cook the pasta in the boiling water until al dente. Reserve 1/4 cup of the cooking water and then drain the pasta. Return the pasta to its pot, add the sauce and the reserved cooking water, and set the pot over high heat. Gently toss the pasta for 30 to 60 seconds and season to taste with salt and pepper. Divide among warm bowls and sprinkle with the remaining 2 Tbs. Parmigiano and 2 Tbs. parsley.