42g Caster Sugar (plus 1 tablespoon for decoration)
170g Unsalted Butter
1 teaspoon Vanilla Extract
Preheat the oven to 160 degrees centigrade. Sieve the plain flour and semolina flour into a bowl, mix in the caster sugar and vanilla extract.
Cube butter and add to dry mix. Rub in the butter until the mixture resembles breadcrumbs. Using your hands, bring the dough together until it is in a ball.
Dust your hands, a rolling pin and a chopping board with plain flour. Roll the dough until it is 1cm thick. Cut into the shape your choice (I used a star cutter but you can roll it out into a round tin, or a rectangle). Transfer the dough to a baking tray covered with greaseproof paper and dust with caster sugar.
Bake shortbread in oven for approximately 35 minutes, or until golden brown. Remove from oven and cut into squares (be careful as the dough is still soft at this point, and very hot!). Leave to cool for about an hour, then enjoy!