Sift the flour into a large glass bowl and leave to one side. In a medium saucepan place the sugar, golden syrup, black treacle, water, spices, orange zest and butter and bring to the boil. Remove from the heat and stir well, making sure all of the butter has melted. Add the bicarbonate of soda and stir until everything has combined.
Gradually add the mixture into the flour, and fold together. The gingerbread will be too hot to handle at this point, so leave in the bowl, cover with cling film and leave for 30 minutes – 1 hour to cool down.
Once cooled, roll out the dough on a floured surface and cut out your desired biscuit shapes. Place onto a baking tray using a palate knife and then bake in a 180ºc oven for 10-12 minutes until golden brown. Remove from the baking tray immediately to make sure they don’t stick and leave to cool on a wire rack.
To make the icing
Whisk the egg whites and cream of tartar in a glass bowl until combined. Add the icing sugar to the mixture and covering any gaps with a tea towel (unless you want icing sugar everywhere) and mix on a medium speed for 8 minutes until the mixture has thickened. Place a into a piping bag and decorate as you wish.