Melt the chocolate and butter in a bowl over a pan of simmering water until smooth.
Leave the chocolate mixture to cool for 20 minutes.
Preheat the oven to 180C
Grease and line a tin with baking parchment.
Whisk together the eggs and sugar until thick.
Add the chocolate mixture to the egg mixture, folding in
Stir in the flour and cocoa powder.
Bake in the oven for 30 minutes