Prepare pasta according to package directions. While pasta is cooking, heat oil in a large, deep non-stick skillet over medium-high heat until hot. Add scallions, garlic and fennel seeds; saute 3 minutes. Combine milk, flour, salt and pepper until smooth. Stir into saucepan. Bring to boil over medium heat; boil until thickened, stirring constantly.
Stir in pumpkin, turkey and cranberries until well blended. Reduce heat to medium; cook until heated through, about 3 minutes. Drain pasta. Place in large bowl. Add pumpkin sauce and toss. Sprinkle with Parmesan cheese. Serve immediately. (Garnished with sprigs of fresh fennel, if desired.)