few drops of blue food colouring
few drops of red food colouring
375g/13oz unrefined caster sugar
300g/10oz caster sugar
pinch of salt
375g/13oz self-raising flour
2 tsp vanilla extract
few drops of vanilla extract
375g/13oz butter or margarine, softened at room temperature
500g/1lb unsalted butter, softened and cut into squares
6 large free-range eggs
5 large free-range egg whites
2-3 tbsp milk
6 tbsp raspberry jam