This is the icing I used for the Cake Balls.
1 1/2 cup of icing sugar
1 cup of powder milk
2 Table spoon of instant coffee
1/2 cup of butter
1/4 cup of milk
1/2 teaspoon of Vanilla extract
Mix everything together.
This recipe has been adapt to use in the cake balls, if you want to use for icing you will need to add 1 1/2 of Sugar and maybe add a little bit more milk.