Pop the chocolate hazelnut spread into a bowl with the milk and heat in the microwave in 10-second bursts until the mixture is runny and viscous, but not steaming hot. This should not take more ...

Reserve one square of the chocolate for decoration and put the rest in a medium heatproof bowl and either melt in a microwave on HIGH for about 1–1½ minutes, or place over a saucepan of gently ...