Prune and apple roll

Prepare a delectable treat reminiscent of a jelly-roll cake, employing a similar technique. However, instead of the traditional jelly filling, opt for a delightful blend of soaked, finely chopped prunes, diced apple, sugar, and luscious marmalade. Spread this flavorful mixture evenly onto the cake before rolling it up. To elevate the experience further, serve this delightful confection accompanied by a velvety custard sauce infused with the enticing essence of vanilla.