Put the egg yolks and sugar in a large bowl.
Beat with electric mixers until the mixture goes pale and thick.
Add marscapone and beat until combined.
It does not matter if it is marbled slightly.
I use a spatula, but you could use a metal spoon.
Do not beat!
If there is any grease, they won't whip properly.
Make sure you rinse and dry your beaters well.
It is very important to retain as much air as possible.
If using a big dish: Put the coffee and liquer in a bowl.
Dip biscuits in coffee one at a time.
Layer in your dish, covering the whole bottom.
Repeat with remaining biscuits and marscapone, finishing with a creamy layer.
Dust with cocoa.
Refrigerate for at least 2 hours, but it works quite well if you leave for up to 24 hours.
If using glasses: Break the biscuits up into pieces that will fit your glasses and do the same soaking and layering as before.