Sift together the flour, baking powder and salt, set aside. In a medium bowl, cream shortening, butter and sugar until smooth. Stir in the egg and milk. Add dry ingredients, stir until combined, then stir in the citron and raisins. Cover and refrigerate dough until easy to handle, about 1 hour.
Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets.
Place remaining 2 tablespoons of sugar into a shallow bowl or saucer. Roll dough into walnut sized balls, dip tops in the egg white, and then in the sugar. Place balls 2 inches apart, sugar side up on the prepared cookie sheet. Bake for 12 to 15 minutes in the preheated oven, cookies should be golden. Cool on cookie sheets. These cookies store and keep well.