Meanwhile, in medium bowl, beat egg yolks and cornstarch with wire whisk. When milk mixture simmers, use ladle to scoop 1 cup into yolk mixture, beating constantly with wire whisk. Repeat with another cup of milk mixture. Pour egg yolk mixture into simmering cream. Cook 3 to 4 minutes, stirring constantly with rubber spatula, until mixture simmers and thickens. Once thickened, cook 2 minutes longer, stirring constantly.