Ingredients
Method
1.Preheat oven to 180°C or 160°C fan. Line base and sides of a 20cm square cake pan with baking paper.
2.Place chocolate, sugar, cocoa and boiling water in a bowl. Stir and stand for 2 minutes, then stir until smooth. Whisk in egg yolks. Fold in flour.
3.Using an electric mixer, beat eggwhites until firm peaks form. Fold gently through chocolate mixture. Pour into prepared pan and bake for 30 minutes, until a skewer inserted comes out clean. Cool in pan. Cut into squares and dust with cocoa to serve.