Preheat the oven to 160ºC.
Mix all the dry ingredients in a bowl
Beat the honey and butter together adding the lemon zest
Add the flour mixture to the liquid and mix together with a spatula
Divide the mixture into 3cm balls and flatten on a baking tray
Bake for 15 minutes and transfer to a cooling rack
When cool, mix the icing sugar and egg white. Drizzle the icing over the biscuits and allow to set