Preheat oven to 180 degrees C. Prepare baking tin with greaseproof paper.
Melt butter, water and 180g of the sugar in a saucepan and bring to the boil
Add broken up dark chocolate and stir to melt
Whisk together remaining 100g of sugar with the eggs until light and airy
Gently fold in the cooled chocolate mix until just combined
Pour into baking tin and bake in preheated oven for 30 minutes
Allow to cool and leave in the fridge for several hours before serving.
Serve with cream or a dollop of mascarpone and fresh berries
