Mix the eggs, sugar, and flour to create a smooth mixture.
Melt the chocolate over a bain-marie and add the melted butter. Now fold the chocolate mix into the dough.
Fill small round ramekins up to halfway with the dough mix. Press a third of a Kinder bar into the middle of each filled ramekin. Cover this with a small spoonful of dough mix and bake the cakes at 360°F for 15 minutes.
While the cakes are baking, cut the remaining 12 Kinder bars into thin strips. As soon as the cakes are done, place the strip of Kinder bar on top in rows so that they start to melt.