Using two bowls, separate egg white from the yolk.
Using a mixer, beat egg yolks (yellows) and 1¼ cups sugar until sugar is dissolved. Then add 2 cups brandy (Marsha B. uses 1 cup) and mix well. Note: You can always add more to egg yolk mixture. It is said, “the sugar cooks the yolks” and set aside.
Using clean beaters, beat egg whites until stiff. Gently fold the egg yolk mixture into the egg whites.
Then fold in frozen cool whip and vanilla ice cream. Note: Keep enough cool whip and ice cream in punch bowl to keep eggnog cold. Punch bowl may not hold all the cool whip and ice cream (just keep adding to keep mixture cold).