Preheat your oven to 200°C (390°F). Generously butter four ramekins and dust them with cocoa powder, tapping out any excess. This helps the fondants come out easily and adds a chocolatey crunch.
Chop the dark chocolate into small pieces and melt it together with the butter using a double boiler or microwave in short bursts, stirring until smooth and glossy. The aroma of melting chocolate should fill your kitchen.
In a separate bowl, whisk the eggs and superfine sugar until the mixture becomes pale, slightly thickened, and fragrant—about 2 minutes. This creates a light, airy base for your batter.
Pour the melted chocolate and butter into the egg mixture, folding gently to combine everything smoothly. Add a teaspoon of vanilla extract if you like, for extra depth of flavor.
Sift the flour into the batter and fold it in carefully until just combined—be gentle to keep the batter light and prevent overmixing, which could toughen the fondant.
Divide the batter evenly among the prepared ramekins, filling each about three-quarters full. Smooth the tops with a spatula or the back of a spoon for an even surface.
Place the ramekins on a baking tray and bake for exactly 12-14 minutes. The edges should be set, but the centers will look slightly jiggly—this is key to achieving that molten interior.
Once baked, remove the ramekins from the oven and let them rest for about 1 minute. Then, run a small knife around the edges to loosen and carefully invert each onto a serving plate.
Serve immediately while warm, with a dusting of cocoa powder or a scoop of vanilla ice cream. The crust should crack when you cut into it, revealing the luscious, molten center.
