To make the vienna cream icing, beat 125g butter (at room temperature) until it is as white as possible. Then gradually add 1.5 cups of sifted icing sugar and 2 tablespoons of milk until the icing is smooth and easy to spread. Add about 6 drops of yellow food colouring.
When the cake has cooled, cut it into a 1 shape. Just keep trimming it until it's level and it looks in proportion. Decorate the cake with the icing, then half a pack of smarties.
The kid loved it! Husband rated it $1.80. The kid's uncle said the cake would have have been better as a lamington - you can't win them all...