Chocolate and vanilla custard buns

Method

1. Preheat the oven to 200°C/fan180°C/gas 6. Line a baking sheet with baking paper.
2. Roll out the pastry on a lightly floured work surface to a 5mm thickness and cut into 8 x 10cm squares. Make 4 cuts from the corner of each square diagonally into the middle of the square, stopping halfway (see our how to make Danish pastries for more information). Chill while you make the vanilla custard filling.
3. For the custard, place the vanilla pod and seeds in a small pan with the milk and heat until just below boiling point. Meanwhile, using an electric hand whisk, whisk the egg yolk and sugar together in a small bowl until pale and fluffy, then whisk in the cornflour. Gradually add the hot milk through a sieve (discard the vanilla pod) and whisk until smooth. Return to the cleaned-out pan, place over a low heat and whisk until very thick. Remove from the heat, cover the surface with baking paper (this stops a skin forming) and leave to cool completely.
4. Whip the double cream until it forms stiff peaks, then fold into the custard mixture. Set aside.
5. For the icing, beat the egg white until stiff. Fold in the icing sugar, cocoa and a pinch of salt and mix until soft. Stir in the cream and mix until smooth.
6. Spoon 1-2 tbsp of the custard into the middle of each square, then fold alternate corners over the filling so that they just overlap. Cover with cling film and chill for 20 minutes.
7. Brush with the egg and bake for 18-20 minutes until golden. Cool for 5-10 minutes, dollop some icing in the middle of each pastry and serve warm.