The problem was, the topping didn't work well for me! In fact, most of it ended up on the floor of the oven as it ran off the cake. The flavour was fine - a sort of caramelised coconut macaroon - but as well as just sliding off the cake, what was left didn't stick well, making the cake difficult to cut and serve.
I think part of the problem may be that UK baking tins are different in size to Australian tins - the recipe states using a 1kg capacity tin, whereas standard UK loaf tins are 450g or 900g. The difference didn't seem enough to matter to me, and indeed, it didn't for the cake itself. However, the cake rose above the top of the tin, and domed in the middle, meaning there was nothing to stop the topping sliding off as it warmed up again in the oven.