Bourbon and Dark Rum Eggnog

In a large bowl with an electric mixer, beat the egg yolks with the sugar until the mixture is thick and pale with ribbons when the beaters are lifted. In another large bowl, beat two thirds of the egg whites until they hold soft peaks. In another large bowl beat the cream until it holds soft peaks. Fold the whites into the yolk mixture until the mixture is combined well and fold in the whipped cream gently but thoroughly. Pour the mixture into a large punch bowl, whisk in the bourbon, the rum, the vanilla, the milk, and the salt. Chill the eggnog, covered, for at least four hours, or until it is cold. Just before serving, in a bowl, beat the remaining three egg whites until they hold soft peaks, fold them into the eggnog, and sprinkle the eggnog with the nutmeg and the cinnamon.