Whisk cocoa, sugars, and salt together in small saucepan then slowly whisk in water.
Place saucepan over medium heat and continue to whisk until cocoa and sugars are dissolved and it starts to simmer. Do not boil or you will get a burnt taste. We're not trying to reduce because we aren't using a lot of water.
Remove from heat and whisk in vanilla.
Allow to cool. Store in squeeze bottle or mason jar.
Mix with milk or use as a topping.
* I offer my recommendation for sugar. I opted for the least I could use without compromising the flavor. If you would like it sweeter, add 1 - 2 more tablespoons.** If you like a thicker syrup, use ¾ cup of water. For a thinner syrup, use 1 cup.