Beat the egg yolks into a thick cream. Let the sugar trickle down. Only when there are no more sugar crystals crunching in the cream, add the amaretto. Finally mix in the mascarpone.
Layer the ingredients in a 1 glass bowl as follows: a couple of amaretti biscuits - spread half of the cream over it - another layer of amaretti biscuits - put the rest of the cream on top. Finally, decorate the surface with the remaining amaretti biscuits.
The cream should sit for about 1 hour. (Not much longer, otherwise the cookies will become too soggy.)