Mix the 8 egg yolks with the sugar, vanilla extract and the pinch of salt until you have a creamy mix.
Mix just for a few second the mascarpone, before you add it to the egg yolks mix. Mix both for a few second and set apart
Mix the coffee liqueur with the expresso
Dip half of the ladyfingers very quickly into the coffee, and line the bottom of a square dish and then the egg-mascarpone cream and repeat. The last layer have to be from the egg-mascarpone mix
Add the cocoa powder on top and refrigerate for 4-6 hours