In saucepan, whisk granulated sugar with cornstarch; whisk in milk. Stir over medium heat just until steaming.
Whisk 2 eggs; whisk in half of the hot mixture in slow steady stream. Gradually whisk back into pan; cook over medium-low heat, whisking, for 15 minutes or until thickened. Stir in vanilla.
Transfer to bowl; place plastic wrap on surface. Refrigerate for 2 hours or until chilled or up to 2 days.