In saucepan, whisk cocoa, sugar, and salt until combined.
1 cup unsweetened cocoa powder, 1 cup granulated sugar, ¼ teaspoon kosher salt
Whisk in water, and heat the mixture over medium heat, stirring frequently, until it comes to a boil. Turn the heat down, and simmer for 3 minutes, stirring frequently, until thickened slightly. Sauce will thicken more as it cools.
1 cup water
Remove from heat, and stir in vanilla extract.
2 teaspoons pure vanilla extract
Cool to room temperature and refrigerate. The sauce will thicken more once it's been refrigerated.
Notes
How to use: This recipe makes a chocolate syrup that is similar to Hershey's chocolate syrup. Use it to top ice cream, pancakes, to make chocolate milk, etc.
Storage: The recipe makes two cups. Store it in a covered container, squeeze bottle, or clean jar. It will keep for up to 3 months if stored properly.