• Pre-heat the oven to 230C or gas mark 8.

For the custard filling

• In a saucepan, gently dissolve the caster sugar in 250ml of water along with the cinnamon stick and lemon zest.
• Heat the sugar syrup until it begins to boil before reducing to a simmer for 3 minutes.
• Place the syurp to one side and let it cool completely.
• In a bowl, mix together the plain flour and cornflour.
• Add some of the milk and stir until it forms a smooth paste.
• Heat the reamining milk in a saucepan and bring to the boil, stirring frequently.
• Once it has reached boiling point, slowly pour it into the bowl of flour, whisking well to make sure there are no lumps.
• Once all of the milk has been incorporated, remove the cinnamon stick and lemon zest from the sugar syrup and whisk the sugar syrup into the milk and flour.
• Next add the egg yolks, one by one, whisking well.
• Finally, whisk in the whole egg followed by the seeds of the vanilla pod.

For the pastry cases

• Dust a clean flat surface with the flour.
• Roll the pastry out into a long rectangle (roughly 50cm long) until it is only 1mm thick (in other words, as thin as you can get it!)
  
• Spin the pastry until the long edge is facing you then dust with the icing sugar and nutmeg.
• Roll the long edge of the pastry towards you as tight as possible.
• Cut the pastry sausage into 12 equal pieces.
• Place those pieces on their end, so the spiral is facing up.
  
• Roll the pieces into disks roughly 1mm thin.
• Lightly grease a muffin tin and gently ease the discs into the tin - using a wet finger to push the pastry into the corners.
• Place the muffin tins on to an oven shelf in the centre of the oven before filling with the custard until they are almost full.
• Cook for 20 minutes or until the pastry has puffed up and the top of the tarts are scorched.
• Remove from the oven and allow to cool for 10 minutes before dusting with a little icing sugar.