Preheat the oven to 180°C and grease two lined baking trays.
Beat the butter and sugar until light, then beat in the egg yolk.
Sieve in the flour and spices, adding enough milk to form a soft dough.
Divide the dough into two equal halves.
Knead currants into one half and roll it out to 5mm thickness.
Cut into rounds, place on trays, sprinkle with sugar, and bake for 15 minutes.
Cool the fruited biscuits on a wire rack.
Roll out the second half of the dough to 5mm thickness and cut into shapes.
Bake the shaped biscuits for 10-15 minutes at 180°C and let them cool.
Mix icing sugar with sieved lemon juice and water until smooth but stiff.
Tint batches of icing with food coloring and pipe decorations onto the cooled biscuits.