Although a standard pack of Jaffa Cakes holds 12, when helping ones self it’s more natural to think in terms of the height of the stack which one can acquire. As soon as the available Jaffa supply dwindles to single digit figures tension arises. This is one of the biggest arguments against those little three packs that you get in cafes and on trains as opposed to bringing your own twin 24 pack.

Lately McVities have been trying to make us feel even better about eating Jaffa Cakes by telling us that there is only 1 gram of fat per cake (less than half that of a Digestive). It's also woth mentioning that all the other Jaffas we reviewed exceeded this figure.

So if the Jaffa Cake is so perfect why mess about with it? Well I suppose with something so popular there is a good chance we’ll be curious to try something new. If we don’t like it we’ll probably just console ourselves with a big old box of the originals so its a win win situation.

Not straying too far from the basic formula, swapping one citrus fruit for two others, this would seem on the face of it the easiest one to pull off. Wrong. The problem here is that we know the smashing orangey bit in the middle so well, that we think we understand its precise taste relationship to an orange. In what is described by McVities as industrial jam, and by me just now as a clear hard set marmalade, we can clearly pick out proper orange juice and zest flavours.

So now we move away from the Citrus fruit into berries, territory scouted out last year by Limited Edition McVities Berry Blast Jaffa Cakes which featured a mixture of raspberry and cherry. Straight comparisons with the original don’t come galloping into view and the blackcurrent flavour is left to speak for itself. I thought it spoke in a slightly German accent putting me in mind of a black forest gateaux. The jam had good sharpness, and the flavour was certainly more reminiscent of the pound and half pick of your own blackcurrents we bagged last summer than solidified Ribenna. This new Jaffa cake could almost be its own man.

Any how enter Cadburys, or more correctly Burton’s with their Cadbury Milk Chocolate covered Jaffa Cake. Burton’s have been going great guns for the last couple of years chucking Cadbury’s chocolate over all sorts of biscuits to great effect. It was only matter of time, considering that they have been making their own Jaffa Cakes for years, before the Cadbury’s Milk Chocolate Jaffa Cake appeared.

To some this is a much more significant alteration than changing the flavour of the jam. As we said in the Jaffa cake equation plain chocolate has always been required to make the whole thing balance. Could it be made to work with the sweeter less domineering milk chocolate? Well just, but the winner here is the orange flavour. Picking out the jam and putting it one on one with the McVities jam its not quite as zesty. None the less it still dominates the Cadburys chocolate so completely taste wise that it’s not at all clear that it has even turned up.

Not exactly a newcomer this one though many people have yet to try it, which is why its almost always on some kind of offer. German bakers Bahlsen have interpreted the basic Jaffa Cake formula but given it some important tweeks in almost every aspect in a bid to build a luxury product. A BMW if you will to our Ford, although hopefully not feeling that it has some God given right to run the rest of us lesser mortals off the roads and with out even bothering to use its indicators at a major junction as such tawdry details are below its stature. Yes I’m losing the metaphor there somewhat.

So what’s going on under the hood? Well the jam is all different, for the get go. Texture wise its much more like a dense and fruity jam than a clear set marmalade. The flavour is authentically orangey perhaps due to real orange pulp finding its way in there. Not only that but it extends right to the edges of the cake, flush. It’s ever so slightly thinner than its pectin packed cousins, but as many have suspected them of systematically shrinking in diameter over the years it has little to worry about on that front.

Right we are going right out on a limb here and taking a look at the latest development in LU Pims range, although these too have apparently been around for a while, I had just not noticed them. The basic LU Pims with orange jam is effectively a French Jaffa cake. Other versions exist with lemon and pear flavoured jam but we’ve never cut them enough slack to investigate those. The main distinguishing feature of the Pims is its elaborate chocolate top shell whose embossed Pims logo I would imagine is meant to evoke the sealing of letters and documents with wax. The whole thing has the feel of being created separately and assembled to form the finished item, in a fashion similar to that other LU staple, the Petit Ecolier biscuit. As such the jam based Pims are even more prone to disassembly than our own Jaffa cakes, but other than that are unremarkable.

However on our last raiding mission to France’s northern ports we secured a pack of mousse based Pims. Citron flavour which is french for a lemon not a type of car (insert your own Jeremy Clarkson French car joke here). LU boldly decided to mess with the very power plant of the Jaffa Cake and swapped out the whole jammy bit for some ‘stuff’ which they are calling mousse. Could we see similar innovations this side of the channel? I doubt it. The mousse is much like something that used to be something else, in the way that ice cream that has been mashed up with a spoon till its melted and gone gloopy is not really ice cream any more. I don’t know what the mousse used to be but it wasn’t that great either, having flavour like one of those pale coloured chewy French sweets rather than a lemon. I would say mousse cakes are going to stay a largely French phenomena much like the Renault Twingo.