1.
Sieve the flour, cocoa powder, baking powder and salt and add the sugar, olive oil and walnut drink. Beat until you get a smooth mixture
2.
Line a baking tray with baking paper and pour the mixture onto it.
3.
Sprinkle the chopped walnuts on top and bake at 350º F for 30 minutes.
4.
Leave to cool before removing from the tray.