Mix the flour, baking soda, salt and spices in a bowl.
Heat the butter in a pan. Add the sugar, maple syrup, ginger and orange zest, stir until the sugar has dissolved. Remove the pan from the heat, allow to cool slightly. Add the butter mixture to the dry ingredients, quickly combine to form a dough, cover and refrigerate for approx. 2 hrs.
Roll out the dough in batches between two cut-open plastic bags to a thickness of approx. 3 mm. Use a round cutter to cut out circles (each approx. 6 cm in diameter), place on two baking trays lined with baking paper.
Bake each tray for approx. 6 mins. in the centre of an oven preheated to 200°C. Remove from the oven, leave to cool on a cooling rack.
On half of the biscuits, use a decorating pen to paint a small dot, stick a red Smartie to it, then use the pen to draw antlers and eyes.
Combine the egg whites with enough icing sugar to make a thick glaze. Coat the remaining biscuits with it. Place one marshmallow on each biscuit, use the decorating pen to draw arms, eyes, nose and buttons.