Preheat oven to 350ºF. Prepare a baking sheet by lining it with paper or a silicone baking mat.
Mix the butter, water, and brown sugar together. Once both ingredients are thoroughly mixed, then mix in the eggs.
Add the baking powder, salt, cocoa powder, and flour. Mix the ingredients until soft dough begins to form.
Scoop dough into tablespoons and roll dough into a ball. Roll each ball in the powdered sugar evenly.
Bake the cookies until they're fluffy and the tops are cracked, about 13-15 minutes. Then, move the cookies to a wire rack to be cooled.
To keep the cookies soft, put them in air sealed container. Will keep for 2-3 days.