Method :

1. In a mixing bowl, add in flour, sugar, salt, and cold butter, mix it until it become crumbly.
   
2. Add in water and knead until it become a rough dough, cover with cling wrap, and put in chiller for 30 minutes.
   
3. Roll the dough to rectangle, put on the butter sheet, and cover it tight with the dough, roll the dough to rectangle and make a book fold, cover and put it back to chiller for 20 minutes.
   
4. Roll again the dough then make another book fold, cover and rest again in the chiller for another 20 minutes.
   
5. Roll the dough to rectangle, sprinkle sugar on the dough surface, roll gently using the rolling pin.
   
6. Tightly roll up one edge to the centre of the pastry. Tightly roll the opposite edge until they meet in the centre. Put in freezer for 30 minutes.
   
7. Preheat oven to 200°c while dough freezes. Line a baking sheet with parchment paper or a silicone mat.
   
8. Slice the frozen dough into 1cm thick per piece. Place on the baking sheet 2 inches apart.
   
9. Bake for 8 to 10 minutes or until sugar starts to caramelize and bubble on the bottom. Flip cookies over and bake until golden brown. Transfer to a wire rack and cool completely. Store in an airtight container for up to 1 week.