Pre-heat oven to 180oc.
Cream the butter and sugar together and then beat in the egg yolks, one at a time.
Shift the flour into another bowl with the mixed spice and then add them to the butter, sugar and egg yolk mixture.
Stir in the currants and add enough milk to make a soft dough, similar to scones.
Roll the dough out and cut out little cakes with a biscuit cutter. Mark each cake with a cross (I did this by pressing on the top with a the back of metal teaspoon) and then place them on a greased and/or lined baking sheet.
Bake the cakes for 10 to 15 minutes, or until golden brown. Leave to cool on a cooling rack!