In a large pot cook pasta according to package directions; drain. Return pasta to pan; keep warm.

Meanwhile, for sauce, in a large skillet cook bacon over medium heat until crisp. Drain on paper towels; coarsely crumbled bacon and set aside. Cut the prosciutto into 1/2-inch pieces; set aside.

In a medium saucepan cook onion in hot butter over medium heat for 4 minutes or until tender. Add prosciutto. Cook and stir over medium heat for 3 minutes. Remove pan from heat. Carefully add wine.

Return saucepan to heat and bring mixture to boiling. Boil gently, uncoverd, for 5 minutes. Stir in the bacon, cream, and milk; bring to boiling. Boil gently, uncovered, for 5 minutes.

Stir in 1/4 cup of the Parmesan cheese and parsley. Immediately pour sauce over pasta, stirring gently to coat. Sprinkle each serving with remaining cheese. Season to taste with pepper. Serve immediately.