1Preheat your oven to 200°C (392°F) and grease four ramekins with butter.
Melt the dark chocolate and unsalted butter together in a heatproof bowl over simmering water, stirring until smooth. Remove from heat and let it cool slightly.
In a separate bowl, whisk the eggs and granulated sugar together until the mixture becomes pale and slightly thickened.
Gently fold the melted chocolate mixture into the egg mixture.
Sift the all-purpose flour and a pinch of salt into the mixture, and fold until just combined.
Pour half of the batter into the prepared ramekins, filling them halfway.
Add a spoonful of raspberry puree into the center of each ramekin.
Cover the raspberry puree with the remaining batter, filling the ramekins almost to the top.
Place the ramekins on a baking tray and bake in the preheated oven for 10-12 minutes, or until the edges are set but the center is still soft.
Remove from the oven and let them cool for a minute before carefully inverting onto plates.
Serve immediately, optionally with a dusting of powdered sugar or a scoop of vanilla ice cream.