Using a fine mesh strainer, sift ½ cup unsweetened cocoa powder over a all saucepan. Whisk in ¾ cup granulated sugar and ½ cup water.
Bring the mixture to a gentle simmer over medium heat, whisking constantly. Once simmering, reduce the heat to low and continue to simmer for 2-3 minutes or until glossy.
Remove the pan from the heat and stir in the ⅛ teaspoon kosher salt and 1 teaspoon pure vanilla extract.
Allow the chocolate syrup to cool slightly and then transfer it to a glass jar. The chocolate syrup will thicken as it cools.
Store the syrup in the refrigerator for up to 2 weeks.
Notes
Make it Sweeter/Less Sweet: You can adjust the sugar up or down by ¼ cup based on your preference for sweetness. Cocoa Powder: Use good quality cocoa powder like Hershey's or Ghirardelli unsweetened cocoa powder for the best results.