Place the chocolate in a heatproof bowl and set aside.
Heat cream and sugar in a pan over low heat, stirring to dissolve the sugar. Bring to just below the boiling point, then remove from heat and pour over the chocolate, stirring until completely melted and smooth. If the chocolate doesn’t melt entirely, you may place the bowl in the microwave for 15-20 second intervals, stirring very well after each, until the chocolate is melted and the mixture is smooth.
Gently stir in the egg yolks and brandy or vanilla extract, then add butter and stir to combine.
Divide chocolate mixture between four 200ml dessert moulds or pots, then chill for at least 2 hours or overnight until just set.
Meanwhile, for salted caramel toffee, line a baking tray with a sheet of foil. Place sugar and ¼ cup (60 ml) water in a pan over low heat, stirring to dissolve the sugar. Increase the heat to high and cook, swirling pan occasionally and brushing down sides with a damp pastry brush, for 4-5 minutes or until a light golden caramel. Quickly, but carefully, pour onto prepared tray, swirling and tilting to spread the caramel. Sprinkle over salt. Cool completely until hardened, then break into shards. Toffee can be prepared up to a day ahead and kept in an airtight container.
To serve, top chocolate pots with whipped cream and sprinkle over shards of salted caramel toffee.