Have a clean working surface ready as the dough is very sticky. Keep all ingredients ready

Sift the flour, baking soda, baking powder, salt and cocoa powder into a large bowl. Add the sugar and mix well.

Rub the cubed butter into the mixture till it resembles breadcrumbs

In another bowl beat the eggs and vanilla extract together. Add this mixture to the flour mixture and mix till it is well incorporated. The dough will be very sticky. Add the chocolate chips if required.

Place the dough on a cling film/plastic wrap, cover and refrigerate it for 3-4 hours or overnight.

When you are ready to make the cookies, cover a large baking sheet with baking parchment. Preheat oven to 170 degrees C. Place the icing sugar in a small bowl

Scoop out a tablespoonful of the dough and roll it into a ball between your palms. Do not flatten them. Work as quickly as you can as the dough can get sticky in no time. Roll the balls into the icing sugar - coat them very heavily as the cracks on top look more prominent when the icing is adequately coated.

Place the coated balls on the baking sheet, spaced well apart. Bake in the preheated oven for 8-10 minutes. (If you are using the choco chips, 10-11 minutes is good). For slightly soft/gooey centred cookies 8-9 minutes is good.

Remove from the oven and allow the cookies to cool completely - do not remove from the baking sheet until almost cooled or they will crumble.

Once cooled completely, store in an airtight container.