In a pan over medium heat add the butter, the water, the sugar and the zest of one orange by using a microplane or a zester or the zesting side of a grater. When the butter melts, add the cognac (or the orange juice) and the cocoa and stir the mixture.

Remove the pan from the heat and add then add the eggs and stir constantly till it becomes like a mixture of hot chocolate drink. Then, add the baking powder and flour and continue stirring till it’s a homogenous mixture.

Butter a baking dish and dust lightly some cocoa powder around the inside of the greased tin (so as to prevent the mixture sticking). Then turn it upside down over your kitchen work surface or sink and knock gently to remove any excess cocoa.

Pour the mixture in the baking dish and bake for about 30-35 mins at 170deg C. I used a dish of 27x18. If you use a different one the baking time may need to be adjusted.

In a clean pan add the water, the sugar and the cocoa over medium to high heat and let it boil. As soon as it starts boiling switch of the stove and let the syrup aside.