Preheat your oven to 425°F (220°C). Grease four ramekins generously with butter and dust them with flour.

In a microwave-safe bowl, combine the unsalted butter and dark chocolate chips. Heat in the microwave in 30-second intervals, stirring until smooth and well combined.

In a separate mixing bowl, whisk together the eggs, egg yolks, and granulated sugar until slightly thickened and pale in color.

Pour the melted chocolate mixture into the egg mixture while stirring continuously to avoid cooking the eggs.

Gently fold the all-purpose flour and 1/4 teaspoon of salt into the batter until just combined.

Pour the batter evenly into the prepared ramekins, filling them about 3/4 full.

Place the ramekins on a baking sheet and bake in the preheated oven for 12-14 minutes, or until the edges look firm but the center remains soft.

Let the cakes cool in the ramekins for 1 minute, then invert onto plates.

Dust with powdered sugar and serve immediately, preferably with a scoop of vanilla ice cream.