Preheat the oven to 150°C/130°C (fan)/gas mark 2. Grease and line a small square, loose based tin in preparation.
Melt the chocolate and unsalted butter in a heatproof bowl suspended over a pan of simmering water.
Remove the bowl from the pan and best in the sugar and flour until smooth. Stir in the eggs, whisky and vanilla extract.
Transfer the batter to the cake tin and bake in the oven for 50 minutes. Leave the brownies in the tin until completely cool before cutting into squares.
For the caramel, simmer the sugar and water in a pan for about 10-15 minutes. Don’t stir the mixture, just give the pan a swish if you think it’s starting to stick.
Remove the pan from the heat and slowly stir in the cream. Add the whisky and salt before returning the pan to the heat for one minute.
Pour the caramel over the brownies and serve immediately. Any left over caramel can be stored in the fridge for up to one week.