Request for “Chocolate Royale” cake

So I'm looking for a recipe for a Chocolate Royale. There are many many cakes online with this name, but none are what I'm looking for. It may be that this cake is unheard of, since the recipe originally comes from my Grandmother and she got it from a friend. BUT, hopefully there's something similar out there on the internet (or from a cookbook?) somewhere. I would be hugely grateful for any help.

What I remember about the cake:

  • Squares of sponge cake layered into a bowl.
  • Rum is added, as part of some 'cement' to keep the sponge squares together. The other ingedients of this 'cement' likely includes chocolate, eggs, sugar etc.
  • Once bowl is full, it is turned upside down and pressure is applied from above to compact the cake for a few hours (perhaps more, unsure).
  • Final result is a dome of chocolate/rum tastiness.

Has anyone come across a cake like this? Hoping to make it before New Years Day! I could just guess from what I remember what to do, but it has been YEARS and I really want to get it right, which I don't have confidence in without a recipe.