Advocaat, a Dutch speciality, is a liqueur made of egg yolks, sugar,
brandy, various other aromatic spirits, and a little hint of vanilla.
The name means "lawyer", and the origin of the name is supposedly that
"those who drink it will talk like one".
Advocaat comes in two different varieties; There is the liquid one, which
is by far the most popular one, internationally. It is used in a number of
drink and cocktails, of which the best known is probably the Snowball.
There is also a thicker Advocaat, which is sold mostly on the Dutch market
and eaten with a spoon. Unlike the liquid one, thick Advocaat also contains
egg white, and is used as an ingredient in many kinds of desserts, like
ice-creams and pastries, but it is also served as an aperitif or digestif.
The traditional way to serve it is in a wide glass or bowl, with whipped cream and cocoa powder sprinkled on top.
Sources: http://www.bols.nl/ and http://www.bolscocktails.com/