Preparation Bring water and sugar to a boil, whisking until sugar is dissolved. Whisk in cocoa and salt and simmer, whisking, until slightly thickened, about 3 minutes. Remove from heat and add vanilla, then cool (syrup will continue to thicken as it cools).
Preparation Bring water and sugar to a boil, whisking until sugar is dissolved. Whisk in cocoa and salt and simmer, whisking, until slightly thickened, about 3 minutes. Remove from heat and add vanilla, then cool (syrup will continue to thicken as it cools).