Preheat your oven to 170ºC/Gas Mark 3.
Line the bottom of a 20cm x 20cm tin with greaseproof paper.
Cream together the softened butter and peanut butter in a large bowl followed by the sugar, then beat in the eggs, vanilla and salt. Add the flour and mix thoroughly, then add the chocolate and fold in. Pour into the prepared tin and bake for 35-40 minutes or until golden brown.
Allow to cool in the tin. Remove and cut into 16 squares.
The time quoted above is an estimate of the time needed until the recipe is ready to eat, allowing for preparation, baking and resting.
As you might expect from Green & Black's, this recipe is indulgent and should be enjoyed as a treat..