From a collection of old Welsh cake recipes, purchased in Wales in 1992. "An impressive cake, its dark base contrasting with a deep meringue topping, is created by the simple improvement on the original of just one extra egg yolk, and one, or perhaps two, egg whites." The recipe says 1 teaspoon cinnamon. You might want a stronger cinnamon taste, so maybe use 1 1/2 teaspoons or to taste. As I haven't tried this cake yet I don't know how long it takes until the meringue topping is set.