A recipe from the Good Food collection.
80 g (2 3/4 oz) unsalted butter, softened
60 g (2 1/4 oz/1/4 cup) cream cheese, chopped
115 g (4 oz/1/2 cup) caster (superfine) sugar
1 teaspoon natural vanilla extract
2 egg yolks
1 1/2 teaspoons caraway seeds
150 g (5 1/2 oz/1 1/4 cups) plain (all-purpose) flour
plum jam, for brushing
icing (confectioners') sugar, for dusting
1. Using electric beaters, cream the butter, cream cheese and sugar in a bowl until light and fluffy. Beat in the vanilla and 1 egg yolk. Add the caraway seeds and flour and stir until a dough forms. Turn out onto a lightly floured work surface, form into a flat rectangle, then cover with plastic wrap and refrigerate for 2 hours, or until firm.
2. Preheat the oven to 180°C (350°F/Gas 4). Lightly grease two baking trays. Combine the remaining egg yolk with 2 teaspoons water, mix well and set aside.
3. Cut the dough in half, then roll out each half on a lightly floured work surface to an 18 × 24 cm (7 × 9½ inch) rectangle. Using a lightly floured sharp knife, cut the dough into 6 cm (2 1/2 inch) squares. Place a scant teaspoon of jam diagonally across the centre of each square, then brush all four corners of the square with the egg wash. Take one corner and fold it into the centre. Take the opposite corner and fold it into the centre, overlapping the first corner slightly, to partially enclose the jam.
4. Brush the tops of the biscuits with the egg wash, then place on the baking trays, seam side up. Bake for 10-12 minutes, or until light golden, swapping the trays around halfway through baking.
5. Remove from the oven and leave to cool on the trays for 5 minutes, then transfer to a wire rack to cool completely. Dust with icing sugar before serving. Store in an airtight container for up to 1 week.