Warning: this is a big cake! It’s made of four separate chocolate sponge cakes. Make each sponge cake one at a time with 4 large eggs, 225g unsalted butter, 225g caster sugar, 175g plain flour ...

Next, spread half of the cake batter into a greased and floured 9×13-inch pan. Evenly sprinkle the cinnamon and sugar mixture over the batter. Then pour the remaining cake batter on top.