Combine the cream, sugar, salt, and butter in a small pot the place over medium heat, stirring frequently until the butter melts and the mixture starts to simmer.
Simmer for just under a minute then reduce heat to medium-low. Add the chocolate in and stir until melted.
Remove from heat and whisk in the cocoa powder and vanilla then return to heat and cook on low for about 30 seconds or until glossy and smooth.
Jar and store in the refrigerator, when ready to use reheat in a saucepan over medium low heat.
