Roll the puff pastry as finely as possible, using icing sugar instead of flour to stop it sticking. When it is rolled, sprinkle it generously with more icing sugar and put it in the fridge to rest for at least half an hour.
Once the pastry has rested cut out 12x8cm circles and put these flat onto a non-stick baking tray. Cover the pastry with a non-stick sheet of paper and a second baking tray. Bake for 10-15 minutes until dark golden, remove the baking tray and non-stick paper and transfer the cooked pastry to a cooling rack while it is still hot.
The plums and cinnamon cream
Reduce the port by just over half the sugar. Add the cinnamon stick and the orange zest. Cut the plums in half and remove the stones, cut them in half again. Put the quartered plums into the port mixture and cover with a piece of waxed paper. Slowly cook the plums over a gentle heat, making sure the liquid doesn’t boil, for about 10 minutes (this will depend on how ripe the plums are). Once cooked, the plums should be soft but not breaking up. Discard the cinnamon stick and the orange peel and leave to cool.
Mix the mascarpone with the icing sugar and the powdered cinnamon, set aside.
To serve, layer the puff pastry with the cinnamon cream and half of the plums. Spoon the remaining plums and their juices around the outside and sprinkle with the sliced mint.