Preheat the oven to 200C/400F/Gas 6.
First you will need to roll out the puff pastry. Be careful when doing this, as it has a high fat content which makes it difficult to work with, if too warm. If you buy frozen puff pastry, it is best to defrost it overnight in the fridge the day before using.
Roll out the puff pastry approximately 3mm/1/8in thick and using a 12cm/4½in cutter or by cutting around a plate, cut out 4 circles. Place directly onto the baking tray and leave to rest for 10 minutes in the fridge.
Using a peeler, peel the apples and cut in half from top to bottom. Remove the core and then slice the apples thinly.
Remove the pastry from the fridge and, using a fork, prick the surface.
Place some apple compote into the middle and fan the apple around the tart base, then finish it by placing some slices in the middle of the tart.
For the vanilla butter, simply scrape the seeds from the reserved vanilla pods and then mix it with 150g/5oz of softened unsalted butter.
Using a pastry brush lightly butter the apples and then sprinkle lightly with sugar.
Place into the preheated oven for 10 minutes, remove and brush with the vanilla butter and place back into the oven for a further 8-10 minutes.
Remove from the oven, brush with butter and leave to rest for 10 minutes.
Serve with clotted cream.