Pour 150 ml boiled water over the dates and let them soak for 10 minutes.
Melt the chocolate in a bowl, set above over simmering water - don’t let the bowl touch the water. Set aside to cool.
Preheat the oven to 180°C. Grease a medium, about 20 cm, springform cake tin and line the base with baking paper.
Whizz the dates with the water in a blender until you get a smooth purée.
Separate the eggs into tow bowls - the egg whites in one, and the yolks in another.
Using electric mixer, beat the egg whites to stiff peaks with a pinch of salt and third of the sugar.
Add the oil to the egg yolks and mix well until combined.
Add the dates purée, the melted chocolate and the sugar. Beat again for a few seconds until combined.
Fold in the ground almonds, cocoa & baking powder, then fold in the egg whites until just combined.
Transfer the mixture into the cake tin, then smooth the top with a spatula.
Bake in the middle of the oven for about 30 minutes. It should remain a bit gooey in the middle.
Let it cool in the tin, then gently open the spring-form and transfer the cake onto a plate.
Dust with icing sugar or cocoa powder. Serve it with custard or brandy cream on the side.