These are from Rachel Allen and she says in the intro "Tired of brownies? Try blondies!" They are very easy to make although came out quite heavy and dense (possibly slightly overcooked?). Not so much as to spoil them though!
1. Preheat oven to 170C/150C fan/325F/gas mark 3. Butter the sides of the cake tin and line the base with greaseproof paper.
2. Sift the flour and baking powder into a small bowl and set aside.
3. In a large bowl, cream the butter and peanut butter together until very soft. Add the sugar, egg and vanilla extract and beat until combined. Add the flour, baking powder and the chopped chocolate and mix to form a dough.
4. Place the dough in the prepared tin and bake in the oven for 25-30 mins or until golden brown and almost firm in the centre.
5. Allow to cool in the tin, before removing and cutting into squares.