1 cup plus 2 tablespoons unsalted butter, plus extra for greasing
1/2 cup plus 1 tablespoon superfine sugar, plus extra for sprinkling
2 cups all purpose flour, sifted
2/3 cup seminola or 1 cup cornstarch

Preheat the oven to 300ºF. Butter a 9 inch square pan. Cream your butter and sugar together with a whisk or wooden spoon until pale, light and fluffy. Add the flour and semolina or cornstarch. Mix very lightly with a wooden spoon and then your hands until you have a smooth dough.

Transfer your dough to a floured surface and roll it out until it’s an even 1 inch thick all over. Press the rolled-out dough into your pan, poling it into the corners with your fingers – don’t worry about it having to look perfect. Prick the dough all over with a fork, then pop it in the preheated oven for 50 minutes until lightly golden.

While it’s still warm, sprinkle with a generous dusting of sugar. Allow the shortbread to cool slightly, then cut into 12 chunky finger-sized pieces.