Preheat oven to 180c / 160c fan / gas 4
Grease a 4cm deep rectangular tin 28cm x 19cm, and line with baking paper
Melt the butter in a small pan. Remove from heat and stir in the cocoa, leave to cool for 10 minutes
Whisk the eggs, sugar and vanilla extract together in a large bowl until pale and foamy
Stir in the cooled cocoa mixture, flour, baking powder and chilli powder
Pour mix into tin
Bake for 35 mins or until top is firm and centre is still soft
Cool for 10 minutes and then turn out onto a cooling wire
When cold cut into 16 squares and dust with icing sugar
