Well, gentlemen, I decided to try the plum pudding (Christmas pudding) with a generous dollup of Cream Cheese Frosting. It tasted very similar to our (Americans') version of Carrot Cake.
I liked it very much. Thank you all for the discussion.
I think I might have luck with it if I use algebra to extrapolate.
A man named Kellogg created Postum in the 1800s as a substitute for coffee; it didn't really catch on until the 2nd World War, when the US War Ministry began to ration coffee.
I tried Postum in the 1980s and loved it. I shed a silent tear when they stopped making it in 2004 or so. Postum tastes somewhat like molasses, which in turn tastes somewhat like treacle in the UK.
If I could find the Camp Coffee I'd buy it in a heartbeat, but even World Foods doesn't carry it. I will have to send away for it.