Preheat the oven to 200°C.
Peel the apples, cut into quarters and remove the core.
Heat a frying pan until hot and add the sugar. Melt, without stirring, to obtain a caramel and then add the butter and the apples. Lower the heat and allow the apples to caramelise.
Place the apples in the base of inividual tart tins.
Cut the puff pastry into 6 discs and use them to cover the apples. Pierce a small hole in the centre of the pastry, this will allow the steam to escape as the tarts cook. Transfer to the oven and cook for 20-25 minutes until the pastry is golden brown.
Keep warm but allow to rest for at least 15 minutes before serving.
Place the Calvados, double cream and sugar in a bowl. Whisk until thick and then shape into quenelles to serve alongside the tarts.
Melt the sugar without stirring to form a caramel. Remove from the heat and whisk in the butter and two generous pinches of salt. Return to the heat and whisk until the caramel turns a dark golden colour. Remove from the heat and whisk in the cream.
Drizzle over the tarts to serve.
«Watch the sugar all the time when making caramel, swirling the pan to prevent it from catching on the bottom of the pan and burning.»