Set your over to 180°C/160°C fan/350°F/Gas mark 4.
Cover your baking sheet with a piece of greaseproof paper (baking parchment).
Sift your flour, salt, cornflour and bicarbonate of soda together and set aside.
Beat together your softened butter and sugars for 2-3 minutes until soft and pale. Wipe down with a spatula mid way to ensure everything is mixed in equally.
Add in your vanilla extract, your egg and 1 desert spoonful of flour and beat until combined.
Beat in the remainder of your flour mixture, starting slowly and increasing to a medium-high setting, until it starts to form clumps. Again wipe down with a spatula mid way to ensure everything is evenly mixed.
Mix in your chopped white chocolate and freeze dried raspberries with a wooden spoon.
Roll a ball of dough to a size of about 4cm, then flatten out to a depth of about 1cm.
Ensure there are 4 to 5 chunks of chocolate in each cookie, if not enough press another chunk into the dough.
Take a whole raspberry and place in the centre of your flattened cookie dough.
Fold the dough over the raspberry to hide it.
Roll back into a ball shape again.
Repeat so that you have 18 cookies.
Place the cookies balls onto your prepared baking tin and freeze for no more than 10 minutes.
Bake in the centre of your oven for 12 minutes, the cookies will be a light golden colour when ready.
Leave to cool for 5 minutes on your baking tray before removing to a cooling rack and allow to cool completely.