Cook pasta as directed on packaging and drain. While pasta is cooking, heat extra virgin oil over medium-high heat in large frying pan. Cook mushrooms in olive oil until tender; remove and set aside. Combine shrimp, Champagne and salt in pan, and cook over high heat. When liquid starts to boil, remove shrimp, and add shallots. Boil for 8 minutes (until reduced to about half a cup). Stir in ¾ cup of cream and boil for 2 minutes. Add shrimp and mushrooms to sauce, heating through. Add salt and pepper. Toss hot, cooked pasta with remaining ¼ cup of cream and freshly chopped parsley. Spoon shrimp with sauce over pasta, and top with Parmesan cheese.