10 Ounce(s) chocolate, semi-sweet chips
2/3 Cup(s) cocoa powder
1/3 Cup(s) sugar
3/4 Cup(s) syrup, light corn
1/3 Cup(s) cream, heavy
1 Pinch(s) salt
1 Teaspoon(s) vanilla extract
3 Tablespoon(s) cut into pieces butter, unsalted
1. Melt chocolate in small heat-proof bowl set over pan of almost simmering water until smooth, stirring once or twice. Turn off heat and whisk in cocoa until dissolved; set aside.
2. Warm sugar, corn syrup, cream, salt, and 1/3 cup water in medium, heavy-bottomed, nonreactive saucepan over low heat without stirring until sugar dissolves. Increase heat to medium-high; simmer mixture, stirring frequently, about 4 minutes.
3. Turn off heat and whisk in vanilla and butter. Cool mixture slightly, about 2 minutes; whisk in melted chocolate. Serve warm. (Can be refrigerated in an airtight container at least 10 days before serving; reheat over simmering water or in microwave for 1 to 1 1/2 minutes, stirring several times, until sauce is shiny and completely smooth.)