I first made this, like so many good things, by accident. I’d cooked some rhubarb and had some juice left over and turned it into jelly. I then thought that the jelly itself would be mysterious and wonderful as part of a toned-down, but at the same time expanded, trifle. I had some mascarpone in the fridge, so used that in place of the custard and cream of an English trifle. The result is more of a dinner party trifle, but not affectedly so.
If you’ve got a suitable glass bowl or di