Preheat the oven to 180°C (356°F).
Mix softened butter, peanut butter, and sugar together.
Add the egg and mix well.
Add flour and baking powder, and mix evenly.
Shape the dough into bite-sized balls.
Place them on a baking tray and press with a fork to create a pattern.
Bake in the oven at 180°C for 12-15 minutes.
Let them cool to finish.