Grease two ramekins generously with butter, then dust with cocoa powder, tapping out the excess.
1 tsp cocoa powder, butter or oil
Melt the chopped chocolate and butter together in a heatproof bowl, either in the microwave in 20-second bursts or over a double boiler, stirring until smooth.
100 g dark or semi-sweet chocolate
In a separate bowl, whisk the eggs, sugar, and salt until slightly pale and frothy, about 1–2 minutes.
2 large eggs, 2 tbsp sugar, 1 pinch salt
Pour the melted chocolate mixture into the egg mixture and fold gently. Add the flour and fold just until no streaks remain.
2 tbsp all-purpose flour
Divide the batter evenly between the prepared ramekins.
100 g unsalted butter
Preheat oven to 200°C (390°F) and bake for 9–10 minutes, until the edges are set but the center still looks soft.
Let the cakes rest for 1 minute, then run a knife around the edge, place a plate on top, and flip to unmold.
Serve immediately, dusted with powdered sugar or topped with ice cream.
