Cook's Tip: Letting the mixture sit for at 24 hours before serving allows time for the flavors to merge together and the alcohol to mellow.
Keep all liquids very cold and refrigerate until ready to use.
Lightly whip cream until soft and thickened. Do not overbeat, or whipped cream will be too hard to incorporate into finished drink.
In the bowl of an electric mixer, beat the egg yolks with the sugar until light and frothy. Gradually add the liquors and the half and half, alternating between the two and starting and ending with the half and half.
Place the egg whites in the bowl of a stand mixer and beat until soft peaks form. Stir beaten egg whites into the yolk mixture, and then stir in the whipped cream. Refrigerate until ready to serve, then top with freshly grated nutmeg to taste.
Makes about 12 cups (3 quarts).