Shortbread relies on really good-quality unsalted butter for its flavour, so don't skimp on this and never use margarine! The high butter (or shortening ) content helps to keep the gluten in the flour short and soft. But, for that delectable, friable texture, it's also important to keep a light hand. Overworking the mixture will make the dough oily; it will also develop the gluten in the flour and make the shortbread tough.
You need to choose your flour carefully. Most recipes call for a 2:1 mix of plain wheat flour and rice flour or cornflour, for a very soft texture, but you can also use semolina for a slightly crunchier result. Sifting in the flour is a valuable step that helps to keep the shortbread light and melting.
And the final crucial thing to remember is that shortbread must be only barely coloured, never browned. So, don't forget it's in the oven...
Preheat the oven to 170°C/Gas Mark 3.
Put the softened butter into a bowl. Using a wooden spoon, gradually work in the sugar until it is well mixed and forms a soft paste.
Sift in the flour and rice flour. Using a fork, bring together lightly to form a soft, crumbly dough. It's hands-on (or in) time now: bring the mix to a soft, pliable, crack-free dough by kneading it as lightly as possible.
For biscuits, place the dough between two sheets of lightly floured greaseproof paper.
Using a rolling pin, roll out to a 5mm thickness. Remove the top paper and cut out biscuits using a 6–7cm fluted cutter or a shaped biscuit cutter (heart, star, leaf, etc.).
Place the biscuits on the baking sheets and prick the surface with a fork.
For a shortbread round, lightly press the dough into the loose-based 20cm flan tin or sandwich tin, or shape into a round, about 2cm thick, by hand.
To finish the edge, pinch into little flutes with your thumb and finger. Prick the surface with a fork.
Bake the shortbread in the oven until very lightly coloured; allow about 20 minutes for biscuits, 30–35 minutes for a shortbread round.
Dredge with sugar and place on a wire rack to cool. Shortbread will keep for up to 4 weeks in an airtight tin.
