Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Cook and drain pasta shells as directed on package.
In medium bowl, mix 1/2 cup of the basil leaves, the chicken, cottage cheese and egg. Spoon about 1 heaping tablespoon mixture into each cooked pasta shell.
Pour pasta sauce into baking dish; spread to evenly coat bottom of dish. Place filled shells over sauce, filled sides up. Drizzle Alfredo sauce over shells. Sprinkle with Parmesan cheese. Cover tightly with foil.
Bake 35 to 45 minutes or until sauce is bubbly and shells are hot. Sprinkle with remaining basil.