Step 1: Preheat your oven to 425°F (220°C). This high temperature is crucial for achieving that perfect molten center.
Step 2: Grease each custard cup or ramekin generously with butter and dust with flour. This ensures that the cakes will release easily once baked.
Step 3: In a double boiler, combine the salted butter and chopped chocolate. Stir continuously until melted and smooth. Remove from heat and let it cool slightly.
Step 4: In a mixing bowl, whisk together the powdered sugar, whole eggs, and egg yolks until well combined and slightly frothy.
Step 5: Pour the melted chocolate mixture into the egg mixture, stirring gently to combine. Be careful not to scramble the eggs.
Step 6: Sift in the ⅓ cup of flour and fold gently until just combined. The batter should be smooth and glossy.
Step 7: Evenly distribute the batter among the prepared ramekins, filling each about ¾ full. This ensures there’s enough room for the lava to flow.
Step 8: Place the ramekins on a baking sheet and bake for 12-14 minutes. The edges should be firm, but the center will look soft. Do not overbake; the magic happens in those last few minutes.
Step 9: Once out of the oven, let the cakes rest for 1 minute. This will help them set slightly and make them easier to plate.
Step 10: Carefully invert each ramekin onto a plate. Dust with powdered sugar and top with fresh berries and a scoop of vanilla ice cream. Enjoy immediately while the center is still warm and gooey!