This is my grandmother's recipe:
12 eggs separated
2 1/4 cups gran sugar
4 cups amaretto (brandy is also a good sub)
2 cups spiced rum
4 cups milk
4 cups heavy cream, whipped
Freshly grated nutmeg
1 tablespoon vanilla
Beat the egg yolks well; add sugar and continue beating until smooth and yellow-colored. Slowly stir in the amaretto, rum, vanilla, and milk. Fold in the whipped cream. Whip the egg whites until stiff but not dry. Fold into the nog mixture. Transfer to a punch bowl and sprinkle with nutmeg.