Mix the butter with the peanut butter and sugar until frothy. Add egg, flour, baking powder and finally the peanuts.
Shape the dough into 24 balls with your hands and place them on two baking sheets lined with baking paper.
Bake in a preheated oven at 150 degrees fan-assisted for about 10 minutes. The biscuits should be golden brown on the edge and a little soft in the middle.
Remove the biscuits with the baking paper from the tray and let them cool on a wire rack.