Preheat oven to 325 °F. Butter and flour six 6-oz custard cups. Mix chocolate and butter in metal bowl. Set over saucepan of simmering water; stir until smooth. Cool slightly.
Using electric mixer, beat eggs, yolks and sugar in bowl until pale and thick, about 10 minutes. Reduce speed; gradually beat in flour. Add chocolate mixture and continue to beat until thick and glossy, about 5 minutes. Divide among prepared cups. Bake until cake is set around edges but center moves slightly when cup is moved, about 12 minutes. Cool slightly. Run sharp knife around edge of cups. Turn out onto plates.
One of France's finest chocolate makers inspired this dessert, which is baked until cake like at the edges but still soft in the middle. When the center is cut, it runs out to create a sauce.
*** (preferably Valrhona)
Serves: 6 in individual cakes
Serve warm with ice cream.