Preheat the oven to 160°C/325°F/Gas mark 3. Lightly flour the mould and line a baking sheet with non-stick baking paper

Sift the flour, cornflour and sugar into a mixing bowl. Rub the butter into the flour & sugar mixture until it binds together and you can knead it into a soft dough

Place the dough into the mould and press to fit neatly (I went over it a couple of times with a rolling pin). Invert the mould on to the baking sheet and tap firmly to release the dough shape (I had to give mine a big old bang on our kitchen table!)

Bake for 35-40 minutes, until pale golden in colour

Sprinkle the top of the shortbread with a little caster sugar and cool on a baking sheet

Cut the larger rounds into ‘petticoat tails’ while still warm