On a chopping board using a sharp knife, chop the white chocolate into chunks.
Whisk the flour, bicarbonate of soda and salt in a bowl. Set aside.
Beat both sugars together briefly in an electric stand mixer to get rid of any lumps.
Add the butter and cream together on a medium/high speed until light and fluffy.
Beat in the egg and vanilla until just combined.
Fold in the flour by hand with a spatula, it should form a crumbly dough.
Tip in the white chocolate chunks and mix briefly to evenly distribute. Chill dough for 1 hour. DO NOT SKIP CHILLING
Shape the dough into balls using an ice cream scoop then chill again for 1 hour. Preheat your oven to 180°C/160°C Fan (170°C/365°F). DO NOT SKIP CHILLING
Place about 6 chilled cookie dough balls on a large baking tray. (You will likely need to bake in batches.)
Bake for 8-10 minutes until thick and golden. Allow to firm up on the tray for a few minutes before transferring to a wire rack to cool completely.