Add sugar.

In the melted chocolate+butter+sugar mixture, add 2 spoons of flour.

Add the eggs and mix it.

Put the batter in the round baking sheet (put the baking paper on the bottom and some butter around the edges first).

Bake for 25 mins on 180℃. The inside should still be a bit moister - that gives it the look of a pie. But if you wish can bake it 10mins longer and the inside should be completely dry.