Melt the butter and the dark chocolate in a water bath.
Puree the dates with as little liquid as possible. Separate the eggs into two bowls. Beat the egg whites to a stiff snow.
Add the yolk to the dates. If you prefer sweeter cakes, add 1–2 spoons of raw sugar. Beat the mix to a creamy homogeneous mass then slowly add the coconut flour and starch, add the melted chocolate-butter slowly and mix well with a whisker. Carefully fold in the snow.
Fill the cake mold with baking paper.
Pour the creamy mixture into the pan and bake in the raw for about 30 minutes. Once cold, sieve cocoa powder over it.