Put gelatine powder and water into a small pot and boil until dissolved

whisk egg whites and castor sugar until stiff (3-5mins). Mix in vanilla and gelatine. Divide into 4 portions.

colour one portion with red, one portion with green, one portion with yellow and leave one portion uncoloured.

pour yellow portion into a 7" square pudding pan and leave to set in the fridge before adding yellow, white and red portion respectively.

chill in the fridge until firm or overnight. Cut into pieces, coat with desiccated coconut before serving