In a bowl, cream together butter, sugar, and vanilla with electric beaters for 1 minute.
Add eggs and beat for another minute until fluffy.
Stir in the flour and milk until combined.
Pour the batter into a lined slice tray and bake at 180°C for 30 minutes.
Let the cake cool completely in the fridge, ideally overnight.
Once chilled, cut into your desired size pieces.
For the Icing: Whisk together icing sugar, cocoa, butter, and boiling water.
Assembly: Dip each cake piece in chocolate icing using a fork, letting excess drip off.
Roll in desiccated coconut and set on a rack over a tray to catch drips.
