Place the chopped chocolate, butter, and vanilla in a large bowl and set aside.
In a medium saucepan over medium heat, whisk the cream, maple syrup, brown sugar, and cocoa powder until the sugar dissolves. Reduce heat and simmer for 5 minutes, whisking constantly.
Pour the mixture over the chopped chocolate and butter. Let sit for 1 minute, then whisk until smooth. Set aside to cool completely to room temperature.