An Eiskaffee is according to wikipedia:

Eiskaffee, literally "ice cream coffee", is a popular German drink consisting of chilled coffee, milk, vanilla ice cream, and sometimes sugar and/or whipped cream

An Esky on the otherhand is one of these:
So how do you make an Esky-Affee?

Simple Answer
Long black (americano) with a dallop of icecream. Vanilla works well.

Long Answer
Take the following:
pic of aero n grinder

  1. Coarsely grind your beans.
  2. Press your Aeropress.
    Note: Some like to add a little sugar at this step as we tend to taste the bitterness as coffee gets colder but ice cream generally has a tonne of sugar in itso give both a go and see how you go.
  3. Dallop of icecream over the top. Alternatively put the long black in the fridge and let it cool. Then add icecream.
  4. Happy days. :)

Enjoy your Esky-affee.

Coffee Esky