Salted peanut butter cookies

Method

1. In a mixing bowl, beat the butter with the sugar and muscovado sugar until pale.
2. Beat in the egg, vanilla bean paste or extract and peanut butter. Sift over and mix in flour, cornflour, bicarbonate of soda and sea salt flakes. Cover and chill for 1 hour until firm.
3. Heat the oven to 180°C/160°C fan/gas 4. Roll heaped tablespoons of the mixture into balls and put on a greased baking sheet, spaced 5cm apart. Flatten very slightly with your hand, then mark with a criss-cross pattern using the back of a fork dipped in sugar. Sprinkle each biscuit with a few sea salt flakes, then bake for 12 minutes until golden. Cool on a cooling rack. Store in an airtight tin.