Whip together egg yolks and sugar.
Add mascarpone cheese and mix until smooth.
Whip egg whites until they form stiff peaks.
Combine the two mixtures to make the cream.
Layer ladyfingers soaked in espresso in a container.
Spread the cream on top.
Repeat layering ladyfingers and cream.
Sprinkle cocoa powder on the very top layer.
Chill in the refrigerator for at least 2 hours.