Preheat the oven to 185°C
Cream butter and sugars, once creamed, combine in the egg and vanilla.
Mix in the flour and the chocolate chips.
Roll into 40g balls, weigh them for the best and most consistent bake! 39-41g acceptable. (At this point, you can refrigerate or freeze them for another day, if you like.)
Place dough balls on a baking paper lined tray. Bake on the top shelf of the oven for 9 minutes from room temperature, 10 minutes from fridge cold and 12 minutes from frozen. They might look a bit blonde at these times , but trust me!
Take out of the oven and leave on the tray to harden for 5 minutes before transferring to a wire cooling rack or they will break apart.
Enjoy warm or store in an airtight container once cool for up to a week.
