Preheat oven to 180 C / Gas 4. Grease 2 large baking trays.
2.
In a large bowl, cream the butter and sugar. Add egg white and treacle; mix until fluffy. Stir in the crystallised stem ginger. Sift together the flour, bicarb, salt, cinnamon, ground ginger and cloves; stir into the egg mixture. When dough starts to come together, mix with your hands to form a smooth dough.
3.
Form dough into 2.5cm balls and roll in demerara sugar. Place balls on a baking tray 5cm apart, and press down with the bottom of a glass dipped in sugar. Bake in the preheated oven for 12 to 15 minutes, cookies should be golden brown. Let the cookies cool on the baking tray for a few minutes before moving to a rack to cool completely. Dip 1/2 of each cookie into icing sugar for decoration.