Peanut Butter Biscuits

125g butter, softened plus extra for greasing
150g crunchy peanut butter
225g granulated sugar
1 egg, lightly beaten
150g plain flour
1/2 tsp baking powder
pinch of salt
15g unsalted peanuts, chopped

1. Lightly grease 2 baking trays with a little butter
2. In a bowl, beat together the remaining butter and the peanut butter.
3. Gradually add the sugar and beat well.
4. Add the beaten egg, a little at a time, beating well after each addition until thoroughly combined.
5. Sift the flour, baking powder and salt into the peanut butter mixture.
6. Add the chopped peanuts and bring all of the ingredients together to form a soft dough. Wrap the dough in clingfilm and leave to chill in the refrigerator for about 30 minutes.
7. Form the dough into 20 balls and place them on the prepared baking trays about 5cm apart to allow room for spreading. Flatten them slightly with the ends of your fingers.
8. Bake the biscuits in a preheated oven, 190C, for about 15 minutes until golden brown. Transfer the biscuits to a wire rack and leave to cool