Chocolate and Pistachio Wedges

From Cherrapeño  

Adapted from The Cookie and Biscuit Bible

200g/7oz unsalted butter, softened
90g/3½ oz caster sugar
250g/9oz plain flour
50g/2oz unsweetened cocoa powder
25g/1oz shelled pistachio nuts, finely chopped
Cocoa powder for dusting

Heat the oven to 190ºC/350ºF/Gas 4. Line a 23cm/9" round tin with baking parchment.

Beat the butter and sugar together until light and creamy. Sift in the flour and cocoa powder and either work in with your hands, or use a hand held electric mixer to bind the mixture together until smooth
(as I did).

Press the dough into the prepared tin. I used a small double ended rolling pin to spread it smoothly to the edges, or you can just use the back of a tablespoon to press the mixture evenly into the tin.

Prick the dough with a fork, sprinkle the pistachio nuts over and gently press them in. Mark into segments with a knife.

Bake for about 15-20 minutes, but do not allow to brown or the cookies will taste bitter.

Remove from the oven and dust with cocoa powder. Cut through the marked segments and leave to cool before removing from the tin.