Mix together the cocoa powder, sugar, and water over medium heat in a medium saucepan. When the mixture comes to a simmer, lower the heat.

Stirring often, cook for about 3 minutes as the syrup thicken. Do not let it come to a rolling boil.

Remove the pan from the heat. Stir in the vanilla and salt.

Allow the chocolate syrup to cool. Then transfer to a glass bottle and store it in the refrigerator.