The Soyer au Champagne is a luxurious and elegant cocktail, often described as an adult version of an ice cream float. It's a delightful blend of cognac, orange curaƧao, maraschino liqueur, Champagne, and vanilla ice cream.
In his 1948 The Fine Art of Mixing Drinks, David Embury's says "At some bars a drink served under the name of "Millionaire" which consists of lime juice, slow gin, and Apricot Liqueur, with a few dashes of Jamaica rum. Since the sloe gin, which is a liqueur, predominates in this drink, I do not regard it as a true cocktail." Embury is more complimentary of what he calls a "Millionaire Royal", proclaiming it to be "a very satisfactory drink."