I’m not sure I’d call this a cake recipe, I think it’s more of a no-bake dessert, but I suppose you could serve it up as a cake. It says it should be made a day ahead, which makes it a great dessert for summer lunchtime bbqs.
I don’t remember Mum making lots and lots of biscuits, but she did make quite a few slices in her time. Unbaked ones like this one were always a favourite, especially in summer when using the oven heated up the kitchen too much. These days with air conditioners that isn’t so much of a problem, but unbaked slices are still a quite a good way to make a sweet treat.