Begin by making the powdered sugar. In a blender or food processor, blend the coconut sugar and arrowroot for a few seconds. Using a fine mash strainer, sift the sugar into a bowl and reserve.
To make the sprinkles, mix together in a medium bowl 150g (which is about 1 cup) of the powdered sugar, cacao powder, water, vanilla, salt, and coffee. Mix everything with a spoon until everything is combined and you have a smooth chocolate mixture.
Line about 4 cookie sheets with parchment paper.
Pour the chocolate mixture into a ziplock bag or pastry bag. Cut a small hole on one end of the bag and begin piping long and thin strips of chocolate onto the parchment paper (see photo below). If you use a pastry bag, use a small piping tip, number 3 or 4.
Allow chocolate to dry at room temperature in a cool, dry place for 24 to 48 hours. After the chocolate is set, cut into small pieces.
Store in an airtight container at room temperature.