Biscuit cake

I learned many things during my numerous trips to England.  I was shopping for antiques at, I think, the Chelsea Antiques Fair.  I had been several places before arriving at the show and after a quick pass through stopped for a cup of tea.  There on a cake stand stood a cake I had never seen before.  I had to try it.  I am not fond of chocolate, but I was drawn to this sublime cake.  It looked like a brownie cake texture except each slice had what I thought was like a Kit Kat bar.  (That was NOT it.  I tried a cake with that bar and it was not a success.) Okay, picture a one-tier cake, chocolate, with a long (English) cookie sandwiched between two layers of brownie mix placed so that each slice had a full biscuit (cookie) the length of the slice.  Topped then with powdered sugar for adornment. It was so delicious but I could not get the woman to part with the name of the cake or the recipe. That was years and years ago and I have not forgotten that cake.  Just this week I learned it is the favorite of the Queen of England and that she has a slice at tea time nearly every day , and, that it is called a biscuit cake! So I Googled it and there were pictures and recipes, some that were not even baked, but none having a cookie running the length of a slice. Instead, all the biscuits had been broken up and cascaded throughout the cake so that when it was sliced all the pieces had a chance to show off. I am still not satisfied, however, because I do not see the exact cake and I failed the one time I dared to try making it.

It looked a bit like this, which was Prince Williams groom's cake. (The one I saw had no icing.)