To make the cream layer, pour the cream into a heavy-based pan and bring to the boil. In a bowl, whisk together the egg and sugar, then pour over the cream and whisk until combined. Rinse out the cream pan and pour in the mixture. Return to the heat and cook gently, whisking all the time, until it reaches 88C – you’ll need a digital thermometer to test this. When it reaches this temperature, it will have thickened and the egg will be cooked. Pass the mix through a fine sieve into a clean bowl. Pour in the whisky, then squeeze any excess water out of the soaked gelatine and add to the bowl. Stir until all the gelatine has melted, then leave to cool a little. Pour into 4 small or 2 large glass dishes, leaving enough room for the jelly, and place in the fridge for at least 4 hours until set.