Instructions

1. Preheat the oven to 180°C.
2. Melt the chocolate and the butter in glass bowl above simmering water. Mix well and let cool a bit.
3. Meanwhile whisk the eggs the sugar until foamy, then add to the melted chocolate. Carefully fold in the flour.
4. Finely chop the chestnuts, then fold into the batter.
5. Line a square pan (about 22cm) with baking paper, then spoon the batter into it and spread out evenly.
6. Bake for about 20 minutes, until almost cooked through (the middle should remain a bit gooey).
7. When completely cooled, slice into cubes.
8. Dict with icing sugar or cocoa powder if you like.