1 teaspoon finely grated orange rind, plus extra to garnish
5 plums, halved, stoned and thinly sliced
1 small egg, beaten
demerara sugar, to sprinkle
sweetened mascarpone, to serve (optional)
Line a baking sheet with baking paper.
Unroll the pastry and cut it into 6 x 10 cm (4 inch) squares. Place on the prepared baking sheet and spread the custard over them, leaving a 1 cm (½ inch) border around the edges.
Put the brown sugar into a bowl with the cinnamon, almonds and orange rind and mix well. Add the plums and toss to coat, then arrange a diagonal row of them across the middle of each pastry.
Brush the border with beaten egg, then bring 2 diagonally opposite corners together and press to seal. Brush the pastries with the remaining egg and sprinkle 1 teaspoon demerara sugar over each one. Bake in a preheated oven, 200˚C (400˚F), Gas Mark 6, for 15–20 minutes, until the pastry is crisp and golden. Serve warm with sweetened mascarpone garnished with grated orange rind, if desired.