Ingredients
110g plain chocolate, broken into pieces
110g butter
110g plain flour sifted
225g caster sugar
2 eggs, beaten
1/2 teaspoon baking powder
Optional: chocolate chunks (we prefer white chocolate)/walnuts etc...
The original recipe that this came from says this amount feeds 8-10 people. They did not base that estimate on my capacity for chocolate. Doubling the quantities yields a decent amount suitable for sharing at conventions.
Method
When measuring out the powdery ingredients filter them through a sieve to make sure there are no clumps.
Preheat the oven to 180°C/350°F/Gas 4.
Put the chocolate & butter in a heatproof bowl. Stand the bowl over a saucepan of gently simmering water. Chocolate burns really easily so never melt it over a direct heat & make sure that the bottom of the bowl doesn't touch the water in the saucepan. Stir the mixture well to make sure the chocolate & butter are fully combined. You don't want any lumps of chocolate or yellow flecks of butter.
When melted take the bowl off the heat & stir in all the other ingredients. Beat the mixture to within an inch of its life. The more consistent your mixture is the better the results.
Spread the mixture into a greased baking tray & bake in the preheated oven for 30 minutes. Don't overcook it or you will lose the nice fluffy texture. The best way to tell whether it is done or not is to gently poke a knife into the centre then pull it out. If the blade has gooey chocolate on it then it needs a bit more baking, if it's clean it's done.
Leave it to cool in the baking tray for 10 minutes (it will sink a little bit). Cut into pieces as desired & leave to cool on a wire rack.