In a large bowl, cream together the butter and sugar. Add eggs and beat until smooth. Stir in the flour, baking powder and salt until well blended. Mix in the orange juice and orange rind.
On a lightly floured surface, roll out the dough to about ½ cm thick. Cut out rabbit shapes with a biscuit cutter. Place the biscuits onto an ungreased baking sheet and lightly press the currants onto them for eyes. Bake in the preheated oven for 8 to 10 minutes. Ice with coloured icing if desired.