- In a medium bowl, beat yolks with sugar and vanilla until smooth and light yellow and very fluffy. Fold mascarpone into yolk mixture. Set aside.
- Dip ladyfingers briefly in coffee and arrange 12 of them in the bottom of a 10×10 inch dish.
- Spread half the mascarpone mixture over the ladyfingers. Repeat with remaining cookies and mascarpone.
- Cover and chill 1 hour. Sprinkle with cocoa just before serving.