Preheat the oven to 180°C.
Mix the butter and sugar until smooth.
Add the egg and mix well.
Sift in the flour and baking powder, then mix evenly.
Add crushed peanuts and peanut butter, then knead the dough.
Shape the dough into balls and place them on a baking tray.
Bake in a 180°C oven for 12-15 minutes, then let cool.