Step 1Bring large pot of salted water to boil and cook fusilli according to package directions until al dente, 10 to 12 minutes. Drain and set aside in serving bowl.
Step 2Remove sausage from casing and break into chunks; each sausage should yield 6 to 8 pieces. Cook sausage in large skillet over medium-high heat, turning so all sides brown, about 10 minutes. Add wine and continue to cook, stirring occasionally until all liquid has evaporated, 3 to 4 minutes. Add garlic and spinach. Break apart spinach as it cooks. Continue cooking until most of liquid from spinach has evaporated.
Step 3Whisk together broth, milk and flour in bowl until flour has dissolved. Add to skillet and combine well with spinach and sausage. Cook over high heat, stirring occasionally until sauce just begins to boil. Reduce heat and simmer, covered, about 5 more minutes. Season with salt and pepper to taste.
Step 4To serve, pour sauce atop pasta in bowl and sprinkle with some cheese. Garnish with basil and pass remaining cheese at table.