Using an electric mixer, beat the egg yolks until fluffy. In a separate bowl, whip the cream and sugar together in a separate bowl. Continue whipping the cream until it thickens but still remains a very thick liquid. It shouldn’t be turning into spreadable cream. Add the orange juice, zest and cinnamon to the cream.
Meanwhile, heat the milk up until boiled in a saucepan over a medium heat then transfer into a bowl over a bain marie. Add two tablespoons of boiled milk to the beaten egg yolks and mix well. Then add the egg yolks to the rest of the milk over the bain marie whisking them in well. Keep the mixture over the bain marie, stirring as it heats up until it becomes a thick custard.
Remove mixture from the heat and transfer to a clean bowl. Add the whipped cream to the mixture and whisk well. Transfer to a plastic container and place in freezer.
Check on the mixture every 1 to 2 hours throughout the day, scraping down the sides and lightly whipping the mixture through as the ice cream begins to set. The ice-cream will need to freeze overnight so it is a good idea to prepare the ice-cream in the morning to allow you time to carry out the scraping/whisking over the first few hours before leaving it to settle overnight. Serve when frozen through, you may need to leave it out a short while to allow it to become scoopable!