Preheat oven to 120 C / Gas 1/2. Lightly grease and flour one 25cm tube cake tin.
In a mixing bowl, cream butter and caster sugar until smooth. Add eggs one at a time, beating well after each addition. Dissolve bicarbonate of soda in buttermilk and add to the creamed mixture.
Place flour in a large bowl and add dates, orange slices and nuts. Stir to coat each piece. Add flour mixture and coconut to creamed mixture. This makes a very stiff dough, so it will be necessary to stir with a wooden spoon.
Pour mixture into the tube cake tin. Bake for 2 1/2 to 3 hours. As soon as cake comes from oven, combine the orange juice and icing sugar and pour over hot cake. Let stand in tin overnight.
You can use two 900g loaf tins OR three 23cm round cake tins instead of the tube cake tin. Simply adjust baking time as needed.