Farfalle with Zucchini and Prosciutto

1 tablespoon butter
¼ cup chopped onion
5 cups matchstick-cut zucchini (about 1 lb)
¼ cup dry white wine
¼ cup thinly sliced green onions
¼ cup reduced-fat sour cream
2 tablespoons extra virgin olive oil
1 teaspoon kosher salt
½ grated lemon rind
1 teaspoon lemon juice
½ teaspoon freshly ground black pepper
2 oz prosciutto, cut into thin strips (about 1 cup)
7 cups farfalle (1 lb uncooked bow tie pasta)

Melt butter in a large nonstick skillet over medium-high heat. Add onion; sauté 2 minutes or until brown. Add zucchini; sauté 2 minutes. Remove zucchini mixture from pan. Add wine to pan; cook until reduced to 1 tablespoon (about 1 minute), scraping pan to loosen browned bits. Combine wine reduction, sliced green onions, and next 7 ingredients (through prosciutto) in a large bowl. Add zucchini and pasta; toss to coat.