Step 1

Add the sugar, cocoa powder, and salt to a small saucepan and whisk well until everything has combined and no lumps remain.

Step 2

Add the water and whisk well. Scrape around the corners of the pot with a spoon to be sure no dry ingredients remain. Once all ingredients have combined to form a thick mixture, place the pot over medium-high heat.

Step 3

Continuously whisk while the mixture simmers. It will start to look glossy and begin to bubble around the 3 ½ minute mark. Keep a close eye on the pot, the syrup can boil over if it is heated for too long, don't allow it to boil.

Step 4

Simmer for another 30 seconds (for a total heating time of 4 minutes), remove the pot from the heat and whisk in the vanilla extract.

Step 5

Allow the chocolate syrup to sit in the pot for 15-20 minutes. Whisk every 5-10 minutes during the rest time.

Step 6

Pour the semi-cooled chocolate syrup into a jar and let it sit until it has fully cooled.

Step 7

Place the lid on the jar and refrigerate for at least 4 hours, it will thicken slightly as it chills. Stir well before serving.