Split the vanilla pod in half and scrape out the seeds. Place the milk, vanilla pod and seeds in a saucepan and bring to the boil.
Beat together the egg yolks and the sugar for 2 minutes and then add the flour. Pour the hot milk over this mixture (removing the vanilla pod) and then return to the heat, bring back to the boil and cook for 3 minutes. Pour the pastry cream into a baking tray lined with cling film. Cover with clingfilm, pressing the film on to the surface of the cream to prevent a skin forming. Place in the fridge and cool thoroughly.
Whisk the cream until thick and chill until ready to use.
Stir the pastry cream to loosen it and then gently mix in the whipped cream. Combine well and then place the mixture in a piping bag.
Heat a pan to hot and then add the sugar to the pan. Allow to melt, without stirring to form a caramel. Tilt the pan to ensure all of the sugar has melted and cook until golden brown. Lower the heat and stir in the butter. Once the butter has melted, add the cream to the pan, stir well and then allow to cool.
Make a small hole in the bottom of each choux bun and then pipe in the pastry cream. Dip the choux buns in the caramel sauce to serve.
«Prepare the pastry cream the day before you need to serve it. The caramel sauce can be kept in the fridge for up to 3 days. »