Heat the olive oil in a large heavy skillet over medium-high heat. Add the sausage pieces using a wooden spoon or heat proof spatula to break up the pieces as it browns. Once the sausage has browned and is cooked through, add the greens and let them wilt. Add the cup of pasta cooking liquid, scraping up the brown bits of sausage. Add the mascarpone cheese and stir as it dissolves into a light sauce. Add the parmesan cheese and season with salt and pepper. Add in the hot pasta, stir well until the pasta is coated with the sauce and serve.