1) Heat a saucepan with water and sugar in it. Stir until all sugar is dissolved. Let the sugar solution boil for 5 minutes.
2) In a small bowl, mix cocoa with some cold water. Pour it into the boiling syrup. Let it simmer for 10 minutes and then add salt. Stir and remove from heat.
3) When the cocoa syrup is cool, transfer it to a bottle or glass jar. Store it in the refrigerator.
4) Use 2 tablespoons of the cocoa syrup for 1 glass of milk.
5) When served cold, it may be topped with whipped cream.
6) You can also serve a hot glass of cocoa milk.