Cream butter and sugar with whisk or mixer till pale and fluffy.
Add in the flour and fold it even.
Place in clingwrap and shape into log shape. Wrap and place in fridge for at least 1hr. (I do this a night before to safe time).
Take out the cookie dough and cut into 8mm – 1cm thickness, to your liking.
Bake it on preheated oven at 180 degree celcius for 16 minutes.
Take out the cookie. Brush with the Yuzu-Gen drink and icing sugar mixture and place the flower on top. Put in the oven again and bake for another 2 minutes.
Once done, take out from oven and brush another layer of the Yuzu-Gen drink mixture and let cool.