Preheat your oven to 190'C (375'F) and line two baking trays with baking paper.
Combine the flour, baking powder, bicarbonate of soda and brown sugar in a mixing bowl. Add the oil and water and mix to combine. Add the currants and knead to create a thick, smooth dough.
Roll out the dough on a floured surface, to about 0.5cm thickness. Cut into circles using a cookie cutter or round glass. Bake on the prepared trays for 14 - 16 minutes or until golden brown; allow to cool on the trays before storing.