Makes about 3/4 cup
You can also use this syrup to make and ice cream soda or egg cream.
Combine the cocoa and sugar in a small bowl. Add 2 tablespoons of the hot water and stir until smooth; add another 1 to 2 tablespoons water if necessary.
When the cocoa mixture is completely smooth, add the remaining hot water. Whisk until the sugar and cocoa have completely dissolved.
Transfer to a small storage container and refrigerate until ready to use.
Store in the refrigerator for up to 1 month.