From what you say, your dessert is very probably Tiramisù. The origins of this recipe go back to the Middle Ages, and it was principaly used by the chefs in the courts of Florence, under the Medici, Venice, under the Doge, and Piedmont, where there was a monarchy. I came across it years and years ago - late 70's if I recall correctly - when I was visiting friends in Piedmont.
In actual fact, the word 'tiramisù' literally means 'pick-me-up', and my friends have always used it not only a dessert, but also, as the name of the dish implies, as a pick-me-up. Everybody had hens, and so it was possible to get fresh or day-old eggs to do it with.
di reston
Enough is never as good as a feast Oscar Wilde
The recipe I learned had a bottom layer of sponge fingers soaked in rum, and then a top layer of the whipped mixture. On top of that, a very thick layer of
cocao powder. Then it was put into the fridge for 24 hrs. When it came out, the layer of cocoa powder had become a rich, creamy, chocolate topping. These days, people like to have two or three layers. Personally I prefer the original one I learned back in the 1970's.
I remember when Tiramisù became popular, and different versions emerged, but it was still essentially the same dessert, and it's remained popular to this day.
Caveat: when you make Tiramisù, it should be consumed same day because of the raw eggs