Pre-heat oven to 180°C: 350°F: Gas 4.
If you use the saffron, drop a few strands into a little warm water or milk and allow to stand for 10-15 minutes.
In a large bowl, cream the softened butter, gradually adding the sugar, beat until light and fluffy.
Beat the eggs yolk and add a little at a time whilst continuing to beat.
Gradually fold in the sieved the flour, spices and salt to the mixture.
Stir in the currants, saffron mixture (if used) and enough warm milk to produce a soft dough.
Divide into 18-24 pieces and shape into flat cakes, marking each with a cross.
Place on a greased baking tray and bake for 10-15 minutes or until golden.