Chocolate Niniche

1. Preheat oven to 210 °C (410 °F)
2.Melt the chocolate over a bain-marie in a saucepan. Add the butter and, once melted, the sugar. Mix well.
3.Break the eggs into a bowl and beat with the flour.
4.Stir the two mixtures together, mixing well.
5.Pour into a greased sponge tin or line the tin with a sheet of aluminum foil.
6.Bake in a bain-marie for 30 minutes (210 °C / 410 °F)
7.Leave to cool and place in the refrigerator overnight.
8.Remove from the tin at the last moment, sprinkle with icing sugar and serve with custard (crème Anglaise).