Prepare the ramekins: Preheat your oven to 425°F. Generously butter the inside of the ramekins, then dust with cocoa powder, shaking out any excess.
Melt the chocolate: In a microwave-safe bowl, combine the chocolate chips and butter. Microwave in 30-second increments, stirring well after each, until completely melted and smooth. Set aside.
Mix the eggs: In a separate bowl, add the eggs, egg yolks, and sugar. Beat for about 2 minutes, until the mixture becomes lighter and slightly thickened.
Combine: Add the flour and melted chocolate mixture to the egg mixture. Mix until everything is completely combined and smooth.
Fill the ramekins: Divide the batter evenly between the prepared ramekins.
Bake: Place in the preheated oven and bake for 12–13 minutes. The edges should be set while the center remains soft.
Rest and remove: Let the cakes sit for 1–2 minutes after removing them from the oven. Carefully loosen the edges with a knife if needed, then invert onto a serving plate.
Serve: Dust with powdered sugar and serve immediately while the center is warm and gooey.
