Preheat oven to 120°c. Line a 22 cm round cake tin with baking powder and grease with butter. Place the plums in the base, cut side down, then set aside while you make the cake batter.

Place the chocolate and butter in a bowl over a saucepan of simmering water until melted.

In a small saucepan heat 100g of the sugar with 75 mls of water until the sugar had dissolved and the syrup has come to the boil.remove from heat and cool before stirring into the chocolate mixture.

Beat the eggs with remaining sugar until very light and fluffy.poor in the chocolate and best until just combined. Carefully pour the mixture over the plums.

Place the tin in pan lined with a clean tea towel and add enough water to come half way up the side of the cake pan. Put in oven and bake for 50 mins our until just set.remove from the oven and allow to cool in the water bath before turning out onto a plate.