Mix the butter, sugar, baking soda, water and vanilla extract together. Add the flour, baking powder and salt. Finally mix in the chopped chocolate.
Shape walnut-sized balls and place on a baking sheet lined with baking paper. Bake the cookies for 7 minutes, then they are nice and juicy and soft. They become crispy if they bake for 10 minutes.
Take the cookies out of the oven and let them harden in the air for 1 minute, then place on a rack to cool.
They taste delicious warm, but are also easy to store!