Melt chocolate and butter, mix with sugar. Add eggs, flour and baking powder.
Pour the dough into a microwave safe dish, e.g., a silicone mold with a volume of 800 - 1000 ml. For a large pan, simply double the quantities and extend the cooking time.
Warning: the dough rises extremely!
Bake in the microwave at 600-650 watts for 6 minutes and then let rest for 5 minutes.
After cooling, garnish with vanilla sauce, cream or powdered sugar. Can also be eaten lukewarm.