1. Grease a 22cm silicon loaf mould.
  2. Sift together the flour, cocoa powder, baking powder, bi-carbonate soda and cinnamon. Set aside.
  3. Place the milk, cream, vanilla, butter and caster sugar into a saucepan. Place on a medium heat and stir until the butter is melted, do not boil. Transfer the milk and cream mixture to a medium bowl. Let the milk and cream mixture cool slightly.
  4. Whisking constantly, add the eggs to the cream mixture.
  5. Stir the sifted flour mixture into the cream and egg mixture to make a smooth batter.
  6. Pour the chocolate cake batter into the prepared loaf mould. Cover with aluminium foil (This is to prevent the water dripping into the cake).
  7. Place 1L of cold tap water into the slow cooker bowl. Place the loaf mould into the water bath in the slow cooker bowl. Place the lid on the top of the slow cooker.
  8. Press the ON/OFF button.
  9. Press the PROGRAM button. Adjust the time to 3 hours. Press SELECT/START to confirm. Adjust the cooking temperature to HIGH. Press SELECT/START to begin.
  10. The slow cooker will beep when the function is complete and will automatically switch to WARM or until the ON/OFF button is pressed to cancel.
  11. Using heatproof mitts, remove the loaf mould from the slow cooker bowl. Let the cake cool slightly before turning out onto a cooling rack. Icing
  12. Place the butter in the bowl of a bench mixer with the paddle beater attached. Beat the butter for 3 minutes on a medium to high speed until it is pale. Add the icing sugar and cocoa powder, beat on a low speed until it is incorporated. Beat for a further 3 minutes. Add the milk and vanilla. Beat again, for a further 1 minute on a high speed. Spread the icing on the cooled cake.