Folding the egg whites in at the end makes this well-flavored eggnog frothy and light and just a little bit lumpy, as opposed to the more traditional thicker and smoother nog.
Beat egg yolks with ½ cup of sugar until lemony. Beat egg whites with the remaining ¼ cup sugar until stiff. Add cream and milk to the yolks and fold in whites. Liquor can be added to the bowl or to cups to taste. Sprinkle generously with nutmeg.
*RAW EGG WARNING: Use caution in consuming raw and lightly cooked eggs due to the slight risk of salmonella or other food-borne illness. To reduce this risk, use only fresh, properly refrigerated, clean grade A or AA eggs with intact shells, and avoid contact between the yolks or whites and the shell.