Meanwhile, cook pasta in medium saucepan as directed on package, omitting salt. While pasta is cooking, combine flour, cinnamon, nutmeg and salt in large bowl; whisk in milk until blended. Melt butter in large saucepan on medium heat. Gradually whisk in milk mixture; bring to boil, stirring constantly. Cook and stir 5 min. or until slightly thickened, (Sauce should be thick enough to coat spoon.) Remove from heat; let stand 2 min. Stir in cheese, then egg.