Set bowl over saucepan containing barely simmering water; heat
mixture until chocolate is melted and whisk until smooth.
When the butter has melted pour the hot cream mixture over the broken chocolate pieces, whisking
gently until the chocolate has melted and the mixture is smooth.
This can easily be done in a microwave — simply microwave in 2 - 3 30 second intervals, mixing in
between until chocolate is melted.
Remove from heat and add dark chocolate while whisking
continuously until chocolate is melted and well - incorporated into the cream mixture.
Set onto a plate or baking tray lined with baking paper, sprinkle with decorations and freeze
again until the chocolate has set.
Whisk the cold milk into the chocolate a little at a
time until the chocolate is completely incorporated into the milk; set aside.
Remove from heat and let cool at room temperature, stirring occasionally,
until the chocolate starts to set at the edge of the bowl.