1. Mix all the dry ingredients, other than the sugar, together in a bowl.
  2. In another bowl, use an electric hand mixer to blend the butter, the molasses, the egg, the sugar, the vanilla, and the maple syrup together for about three minutes, or until completely smooth.
  3. Add the dry mixture gradually to the wet mixture until a smooth dough is formed.
  4. Pat the dough into a bowl, cover it with plastic wrap, and refrigerate for 1 hour.
  5. After 1 hour, preheat the oven to 350 degrees F.
  6. Roll out the dough on a floured surface until it is about one centimetre thick.
  7. Use cookie cutters to cut different shapes out of the dough.
  8. Place the cookies on a baking sheet lined with parchment paper and bake for 12-15 minutes.
  9. Let the cookies cool completely before decorating with the icing.
  10. For the icing: In a bowl, combine the egg white and icing sugar with an electric mixer and whisk 2 minutes, until smooth.