Place the dried fruits in a bowl and pour over the hot tea, orange juice and zest. Cover with cling film, then leave for at least 4 hrs or better still overnight.
Heat oven to 180C/160C fan/gas 4. Grease and line the base of a 2lb loaf tin. Beat together the butter and sugar until creamy, then beat in the egg followed by the flour. Carefully stir through the fruit mixture. Spoon the mixture into the tin, then smooth over the surface with the back of a spoon. Sprinkle all over with a thick layer of demerara sugar.
Bake for 1 hr or until a skewer inserted into the centre comes out clean. Leave to cool in the tin, then turn out, cut into slices and serve.