Crush the ladyfinger biscuits into fine crumbs.
In a bowl, mix the mascarpone, espresso, icing sugar, and vanilla until smooth.
Add the biscuit crumbs and stir until a soft dough forms.
Chill the mixture for 20–30 minutes.
Scoop out small portions and roll into bite-sized balls.
Coat each ball in cocoa powder.
Refrigerate for at least 1 hour before serving.
