Preheat the oven to 375 degrees.

In a mixer fitted with a paddle attachment (or using a hand mixer), mix the flours, salt, sugar and baking powder at low speed. With the mixer running, add the butter and mix until coarse and sandy. Add the milk and mix until almost combined, then add the currants and mix just to distribute them evenly through the dough. Do not overmix; there may still be some flour not mixed in. Turn the dough out onto a lightly floured surface. Knead the dough 10 times. With a lightly floured rolling pin, roll out the dough 1-inch thick. With a biscuit or cookie cutter or a clean empty can, cut out circles about 2 1/2 inches in diameter. Transfer to an ungreased baking sheet with a spatula. Knead the scraps together just until combined, then roll out again and continue cutting out circles until all the dough is used up. Brush the tops of the scones with cream and sprinkle with brown sugar. Bake until light golden brown, about 15 minutes.