Place ⅓ of the chocolate into a food processor and blitz until fine. Remove from the food processor and place into a large, heatproof bowl. Repeat until all of the chocolate is blitzed. Doing the chocolate this way ensures it will melt quickly in the cream, and also saves you having to chop 1.2 kilograms of chocolate!
Place the cream into a saucepan and place over medium heat. Heat until simmering and then pour over the chocolate in the bowl.
Pour the cream over the chocolate and leave for 5 minutes, undisturbed.
After 5 minutes, using a whisk and working from the middle of the bowl, slowly incorporate the cream into the chocolate. Work slowly and your ganache shouldn’t split, but if it does, add 1 tablespoon of hot water and beat in, adding more hot water as necessary. You can also make the ganache in batches if you’d like / don’t have a bowl big enough!
Once the ganache is smooth, leave to cool.
Once cool, place some cling film on your work surface and shape half of the ganache into a half circle. Make a well in the middle, add the salted caramel and then shape the rest of the ganache over the top so you have a huge circular truffle. Wrap the cling film up and around the truffle then place in a bowl big enough to fit the truffle in and place into the fridge for 1 hour.
Once chilled sufficiently, roll the giant truffle in cocoa and serve.