Add the butter and sugar to a bowl and cream together (see notes about rubbing ingredients together instead)
Add the plain flour, cornflour, and vanilla and beat to a dough. Sometimes it can be slightly crumbly, so you just need to knead it with your hands to bring it together
Add in the chocolate buttons and knead/mix through
Tip the dough onto a lightly floured surface and roll out to 1-1.5cm in depth
Cut cookies out using a 7.5cm cutter, and place onto lined trays. I do 6 per tray as they are quite large
Chill the cut cookies in the fridge for 30 minutes, and preheat the oven to 180ºc/160ºc fan
Sprinkle over some extra sugar and then bake the cookies in the oven for 20-25 minutes, or until golden - PLEASE NOTE, if you make the cookies any smaller/thinner, you will need to reduce baking time. Gas ovens may also need less time due to how the heat works
Leave to cool on the trays, and enjoy!
