Due to popular demand here is the recipe for Mary Berry's Chocolate Tray Bake (from the Mary Berry Ultimate Cake Book). The icing can be difficult to make just because of the amount of icing sugar,. (cake making mary berry)
The Improving Cook- Traditional Jam and Coconut Sponge. Make a loaf cake for afternoon tea, or make a traybake to serve with custard, in British school dinners style! Lovely buttery sponge topped with strawberry jam and coconut.