Preheat the oven to 175 degrees Celsius / 345 Fahrenheit top and bottom heat.
Using a hand mixer, beat together the butter, sugar, brown sugar and vanilla extract, adding the egg half way.
Gradually add the flour and baking soda.
Finally, fold in the white chocolate chips and cranberries.
Cover a baking sheet with parchment paper and use an ice-cream scoop (or a spoon) to scoop even balls of dough onto the tray. Make sure you leave enough space between the cookies as they will expand a little during baking.
Bake the cranberry cookies in batches for about 12-14 minutes. Leave to cool and enjoy!