James Martin's lavender shortbread

175g/6oz unsalted butter, softened, plus extra for greasing

100g/3 oz icing sugar

-1 tbsp dried lavender tips (to taste)

100g/3 oz cornflour

200g/7oz plain flour

2 tbsp caster sugar (optional)

For the shortbread, set the oven temperature to 180C/160C Fan/Gas 4. Grease a

30x20cm/12x8in baking tin with butter.

Beat the butter and icing sugar in a bowl until light and fluffy, using an

electric whisk. Fold in the lavender, cornflour and plain flour until the

mixture comes together as a firm dough.

Press the dough into the prepared baking tin using your fingertips to form an

even layer of dough about 1cm/ in thick. Prick the dough all over with a fork

and sprinkle with the caster sugar, if using.

Bake the shortbread in the oven for 12-15 minutes, or until pale golden-brown

and cooked through. Set aside to cool in the tin for a little while, then break

into pieces.