Preheat the oven to 160C/325F/gas mark 3
Use a 900g/2 lb loaf tin.
Combine the coconut and milk and stand at room temperature for 1 hour. Grease and line the loaf tin. Cream the butter, rind and sugar in small bowl until light and fluffy; stir in the sour cream and mix well. Transfer this mixture to a large bowl and stir in half the coconut mixture with half the sifted flour and the baking powder. Then stir in the remaining coconut mixture and flour. Stir until smooth. Pour mixture into the prepared tin. Bake for about 1 1/2 hours. Allow to stand for 10 minutes, before turning on to wire rack to cool. Spread cold cake with icing; decorate with orange wedges if desired. Orange Icing: Sift icing sugar into bowl, stir in butter and enough juice to mix to a spreadable consistency.
