Make the coffee and allow it to cool down in a bowl, waiting for it to reach a temperature of about 40°C.
Then whip the egg yolks with the sugar and gradually add the mascarpone a little at a time, thus obtaining a soft cream.
Soak 30 savoiardi in the coffee, being careful not to steep them excessively, then arrange them in a row in the center of a circular plate. (Place them very close, to create a good consistency)
Spread half of the mascarpone cream on the savoiardi and then add another layer of 30 savoiardi dipped in coffee, and spread the surface with the remaining mascarpone cream.
Store the tiramisu in the fridge until ready to serve. (At least 24h)
Sprinkle with sifted bitter cocoa and serve in wedges.