It's also a good way to use up any slightly stale cake. Bring the raspberries, blackberries and blueberries to the boil in a saucepan with the sugar and a little water. Simmer for a few minutes ...
or the like--triple the recipe and bake in different-size cake pans, perhaps 12 inch, 8 inch, and 5 inch. Brush the largest layer with one third of the syrup, center the second largest layer on top ...