Brew strong black coffee and let it cool.
In a bowl, whisk egg yolks and sugar until pale. Add mascarpone, vanilla, and salt; mix until smooth.
Whip heavy cream to soft peaks. Fold into the mascarpone mixture gently.
Quickly dip ladyfingers in cooled coffee and layer half in a dish. Spread half the cream mixture over them.
Repeat the layers with remaining ladyfingers and cream.
Cover and chill for at least 4 hours or overnight.
Dust with cocoa before serving.
