To ensure consistent baking, preheat the oven to 200°C.
Melt the butter and chocolate together to create a shiny, smooth mixture.
For a light batter, beat sugar and eggs until frothy.
Add the flour and chocolate mixture to the egg-sugar mixture and fold gently.
To make sure the cakes come out of the molds easily after baking, grease them.
Fill molds with batter, then bake for 10 minutes to firm the edges.
Enjoy the melting centers of warm inverted cakes after garnishing them with powdered sugar.