1 espresso (40 ml, about 1 1/4 oz)*
1/2 cup water
1/4 cup sugar
1/3 cup unsweetened cocoa powder
Bring espresso, water and sugar to a boil, whisking until sugar is dissolved. Whisk in cocoa and continue to whisk until thickened. Allow to cool. Can be made and refrigerated overnight prior to serving.
*I used Etiopia Blend Forte from Gourmesso