Break up the chocolate into small pieces, and place them into a medium-sized, heatproof bowl.
Add the muscovado sugar, cream, and sea salt to a small saucepan. Gently heat the mixture over low, stirring regularly, until the muscovado sugar has fully melted, and the mixture is a caramel brown color. Do not allow the mixture to boil.
Pour the mixture from the saucepan into the bowl with the broken chocolate, and whisk continually until a smooth, glossy ganache forms, and all of the chocolate pieces have melted.
Allow the mixture to cool completely before using it to frost a cake. If using this recipe to make truffles, refrigerate the ganache for 4 to 6 hours until it has hardened.