In a small bowl, mix the espresso or coffee with the milk.
In a bain-marie, whisk the egg yolks and sugar continuously until the mixture is creamy and forms ribbons, about 5 minutes.
Remove from the bain-marie and continue whisking using an electric mixer (or a fork) until the mixture cools down. Add the mascarpone cheese.
In another bowl, whip the cream and the remaining sugar until it forms stiff peaks.
Using a spatula, gently fold the whipped cream into the cheese mixture.
Dip the ladyfinger biscuits in the coffee for 2 to 3 seconds. Cover with a layer of the cream mixture and then the cocoa powder.
Repeat the process with the remaining ingredients.
Cover the container with plastic wrap and refrigerate for at least 4 hours or overnight.
