1In medium bowl, beat egg yolks and sugar with wire whisk until thick and lemon colored. In 2-quart saucepan, stir milk and 1 cup of the whipping cream. Add yolk mixture, stirring with whisk. Cook over medium heat 10 minutes, stirring constantly, until mixture just coats a metal spoon.
2Remove from heat; stir in vanilla and 1/4 teaspoon nutmeg. Place saucepan in cold water until custard is cool, stirring occasionally. Cover; refrigerate at least 2 hours but no longer than 24 hours.
3Just before serving, stir bourbon into chilled custard. In chilled small bowl, beat remaining 1 cup whipping cream with electric mixer on high speed until stiff peaks form. Gently stir whipped cream into custard. Sprinkle with additional nutmeg. Serve, or refrigerate until serving time. Eggnog can be stored covered in refrigerator up to 2 days.