Preheat the oven to 210°C (415°F/Gas 6–7). Lightly grease two baking trays.
To make the filling, combine the currants, mixed peel, brandy, sugar and cinnamon in a bowl. Divide the pastry into three and roll each piece out to a 3mm (⅛inch) thickness. Using an 8cm (3¼inch) cutter, cut nine circles from each sheet of pastry.
Place 2 level teaspoons of the filling on each circle. Bring the edges of the rounds up together and pinch to seal. Turn, seam side down, and roll out to 1cm (½inch) thick ovals. Place on the trays, brush the tops with egg white and sprinkle with extra sugar. Make three slashes across the top of each cake, then bake for 15–20 minutes, or until golden. Serve warm.