Preheat the oven to 180°C (356°F).
In a bowl, mix peanut butter, sugar, and egg together.
Scoop out spoonfuls of dough and shape them into balls.
Place the dough balls on a baking tray.
Press the tops with a fork to make a pattern.
Bake in the oven for 10 to 12 minutes.
Transfer to a wire rack and let cool completely.