Steps
1. Soak the ladyfingers in the espresso for a few minutes.
2. Layer the ladyfingers in a bowl.
3. In a separate bowl, mix the mascarpone cheese, egg yolk, sugar and cocoa powder.
4. Spread the mixture over the ladyfingers.
5. Layer the sponge cake over the mixture.
6. Refrigerate for at least 1 hour.
7. Serve chilled.