1. Preheat oven to 180°C/350°F/Gas 4. Lightly grease 2 flat baking trays or swiss roll tins.
2. Put the butter and sugar into a mixing bowl and beat until smooth and creamy.
3. Next, beat in the peanut butter. Finally, stir in the beaten egg and the flour. Mix until smooth.
4. Put teaspoonfuls of the mixture onto the baking sheet (a little apart, to allow for spreading during baking).
5. Bake for 15 minutes if you like them soft in the middle, or for 25 minutes if you like them crisp.
6. When baked, allow to set for about 5 minutes. Transfer to a wire tray to cool. When completely cold, store in an airtight container to keep them fresh.

Peanut Butter Cookies