Remove puff pastry from the fridge and allow to warm for 10 minutes at room temperature. Butter a 12 hole muffin tin and set aside. Unroll the pastry and cut in half. Mix the cinnamon and sugar, scatter over the piece of pastry on the left, then place the other piece on top. Roll up the pastry from the short side into a tight roll, then cut into 12 even pieces.

Place the pastry pieces with the spiral facing up, dust with a little flour, then roll out flat. Press each into the prepared muffin tin, leaving a centimetre of pastry overhanging the rim. Chill until needed.

Heat the oven to 220°C / 425°F / Gas 7, with a baking tray in the top third of the oven.

To make the syrup, whisk together the sugar and water in a small saucepan over medium heat until the sugar is dissolved. Add the cinnamon stick and lemon peel and simmer, uncovered for 5 minutes. Remove from the heat and set aside.

To make the filling, whisk together the egg yolks, egg, milk and cornflour until well combined. Cook over medium heat, whisking constantly until the mixture begins to thicken and bubble. Pour in the sugar syrup while whisking constantly, cook for another minute or two until the mixture is thick again, then remove from the heat. Strain into a heatproof bowl or jug through a sieve to remove any lumps.

Spoon a generous tablespoon of the custard into each of the pastry cases, then cook in the oven for 15-20 mites until golden, puffed and beginning to scorch. Every oven heats differently so this may take a little longer or a little less, keep an eye on them after 15 minutes.

When the tarts are cooked, remove from the oven and allow to rest for 5 minutes. Use a small sharp knife to loosen the tarts from the tin if necessary, then transfer to a wire rack to cool. Dust generously with icing sugar before serving.