Delicious! I adjusted a few recipes I gleamed on the internet. This one has no sugar except for the marmalade, less butter than most, and the marmalade is homemade.
1- Au bain-marie, melt 140 gr of pure dark chocolate (70% or more) with 70 gr of butter plus 30 gr of semi-salted butter. (I used unsalted and demi-sel, both Président.)
2- Meanwhile in a large bowl, mix two whole medium size organic eggs until it doubles in volume. It will become a lighter shade of yellow.
3- When the chocolate and butter have melted, take the mix out of the bain-marie and mix well. Add 200 gr of orange marmalade (for the homemade recipe see here.) Mix all with a spatula.
4- Then add 100 gr of sifted flour and one tablespoon of baking powder. Mix it all well with a spatula and add the egg mix at the very end. Mix again until you get a homogenous consistency.
5- Bake in a prepared baking dish (I used a round one, you can also use a regular rectangular cake baking pan) for 40 minutes at 170ºC.
Let it cool thoroughly before serving.