This recipe is apparently the one that Hepburn used to make her brownies, not too much flour is the key to success.
She supplied it to the 'The Ladies Home Journal' in 1975.
I'm gonna give them a bash soon and I'll let you know how I get on.
2 eggs beaten
pinch of salt
50g dark chocolate
200g white sugar
a cup of chopped walnuts
preheat the oven to 170C/340F/gas mark 3+1/2
melt butter with chocolate in saucepan, add eggs,sugar, a drop or two of vanilla essence, a pinch of salt and the chopped walnuts
add flour, mix well and pour out into a square (20cm) cake tin lined with baking parchment. Bake for half an hour.