Add the egg, sugar, vanilla, along with a pinch of salt into a bowl. Beat with a wooden spoon until pale.
Add the flour and mix in with your fingers until the dough looks like sand.
Add butter and knead in well to form a dough. If the dough is too sticky, add more flour.
Form the dough into a ball and chill in the fridge for 30 minutes.
Preheat the oven to 180°C.
Sprinkle the counter top with flour and roll the dough until as thin and as thick you want your cookies.
Cut out the cookies with a round cookie cutter, to whatever size you want.
Bake in the oven (on an oven tray) for 15-20 minutes.
Once fully cooled, spread the cookies with peanut butter and sprinkle with the chopped peanuts.
