Combine flours, salt, baking powder, sugar and nutmeg in large bowl. Cut in butter until mixture is the consistency of cornmeal. Stir in raisins and/or fruit. Combine potato, whole eggs, yolk and milk in medium bowl. Whisk until no lumps remain. Make a well in the centre of the dry ingredients and add liquids all at once. Stir with fork to make a soft, slightly sticky dough. If necessary add 1-2 tbsp more milk. Press lightly into a ball and knead gently unto floured surface about six times. Roll out dough to ½ inch (1 cm) thickness; cut into triangles or rounds. Place on ungreased baking sheet. Brush with slightly beaten egg white and sprinkle with sugar. Bake at 450° F (230° C) for 13-15 minutes, or until golden.