Peel and cut the pineapple into thick slices of 1cm.
Melt the sugar in a large saucepan to form a caramel. Add the pineapple to the pan and coat with caramel. Add the water to the pan and allow to reduce, turning the pineapple over from time to time. Once the liquid has reduced to a thick syrup, add the rum and flambee the pineapple by tilting the pan towards the flame.
Scrape the seeds from the vanilla pod and place in a saucepan with the milk. Bring to the boil.
Place the egg yolks, the caster sugar, corn flour in a bowl and mix.
Once the milk is boiling, add it little by little to the egg yolk mixture. Return the mixture to the pan and whisk over a medium to high heat for 3-4 minutes, gently bringing it to the boil. Transfer to a bowl, cover with cling film and chill in the fridge.
Whip the double cream until thick and then gently fold into the chilled vanilla cream. Put the finished cream into a piping bag and keep chilled until ready to assemble the mille feuille.
Preheat the oven to 180'C.
Cut the puff pastry into rectangles (5cm x 3cm). Allow 3 per person.
Bake 2/3 of the puff pastry rectangles for 15 minutes with another baking tray on top to keep them flat. Bake the rest uncovered and allow them to puff up.
When the pastry is crisp and golden brown, allow to cool and then dust with icing sugar.
Top half of the flat pastry rectangles with pineapple, cutting the fruit to size as necessary. Place a second layer of pastry on top and pipe on the crème patissiere. Place the final layer of puff pastry on top, dust with icing sugar and finish with a drizzle of the caramel sauce.
«Try adding a pinch or two of Allspice to the pineapple to give it a little Caribbean flavour.»