Line the base and sides of a regular sized loaf tin with baking paper.
Add the chocolate to a medium microwave safe bowl. Microwave in 30 second bursts, stirring after each burst, until melted.
Stir through the butter and golden syrup, until combined.
Add the cream to a separate small microwave safe bowl. Microwave for 1 minute, until hot and steaming.
Add the cream and salt to the chocolate mixture and whisk together, until combined.
Pour the truffle mixture into the prepared loaf tin.
Place into the fridge for 2-3 hours to chill, until it is firm and set completely.
Once the slice is set, remove it from the loaf tin using the baking paper as handles.
Run a large sharp knife under hot water, then dry it with a tea towel.
Use the hot knife to cut the truffle slice into about 15 squares.
Add the truffle slice squares to a bowl and add the cocoa. Toss to coat the truffles in the cocoa.
Serve the truffles decorated with the edible gold leaf, if using.
Use a clean paint brush to apply the gold leaf, to prevent it sticking to your fingers.
