For the filling, whip mascarpone (or cream cheese, or neufchatel) with sugar and vanilla until you no longer see sugar crystals and the cheese takes on a batter-like texture. Do not panic if it's runny, as it will firm up in the fridge.
Cover (I use a resealable plastic container, otherwise go with cling wrap) and refrigerate overnight -- willpower!! -- before serving. You need the time for the just damp ladyfingers to absorb the moisture from the mascarpone (which in turn "pushes" the espresso deeper into the ladyfinger, softening it while firming up the mascarpone further) and you need the filling to set up** to the correct firmness. Just prior to serving put cocoa/ in a fine strainer and shake a light coating on surface, or sprinkle chocolate shavings.
Serve to rapturous acclaim.-J.
Posted by Joke at 8:41 AM