250 g (9 oz) butter, softened
110 g (3 3/4 oz/1/2 cup) caster (superfine) sugar, plus extra for dusting
300 g (10 1/2 oz/ 2 cups) plain (all-purpose) flour
150 g (5 1/2 oz/ 1 1/4 cups) cornflour (cornstarch)
Preheat the oven to 160°C (315°F). Lightly grease two baking trays and line with baking paper.
Use an electric mixer to cream the butter until pale, then gradually add the sugar, beating the mixture until it is pale and creamy. Gradually work in the flour and cornflour, then knead for about 5 minutes, until it becomes a very smooth dough.
Roll out the dough on a lightly floured work surface until it is 5–6 mm (1/4 in) thick and use a 6 cm (2½ in) fluted round cutter to cut out rounds. Put on the prepared trays and use a fork to prick shortbread in a decorative pattern. Dust lightly with extra caster sugar.
Bake the shortbread in the lower half of the oven for 25–30 minutes, or until very lightly coloured and crisp, swapping trays halfway through for even baking. Cool on the trays for 10 minutes, then transfer to a wire rack to cool completely.
Store in an airtight container for up to 3 weeks.
See our how-to video below, via youtube.