Like Battenberg or marble cake, the metre-long cake is a two-tone jigsaw puzzle of a cake. Plain and chocolate sponge stripes with jam filling and covered with chocolate glaze - quite a bit of effort, totally worth it.
This is traditionally known as ‘metre-long cake’, metrowiec, in Poland where it originates from. At least to my knowledge. It is also sometimes called a caterpillar cake (though not the kind involved in legal actions), both names referring to its length – it’s a loooong cake.
But the first name is a lie actually – it’s nowhere near a metre long. Perhaps in the olden days, the days of those lavish recipes of dozens of eggs and pounds of flour, perhaps it was a metre long then. But wouldn’t it in fact be a yard cake then?
Whether it was cut down to size at some point in history or something else happened, it is barely longer than two standard loaf tins lined one after the other – about 60cm in all. What a grandiose name it has! On the other hand Paris-Brest is a mere éclairé, so there.
What is metre-long cake like?
It has a lot in common with Battenberg, as I only realised recently. Both are two-tone sponge baked separately, then cut, sliced and spliced by means of a tasty glue: jam or frosting. Battenberg of course is more of a showman, featuring lurid pink and yellow colours in a chessboard pattern, slathered with jam and wrapped up in thick marzipan just in case it wasn’t rich enough.
Metre-long cake is more modest: tasteful pale and chocolate arranged into vertical stripes when you cut it, jauntily, on a diagonal. There’s no marzipan but a chocolate glaze – not so rich if like me you use dark chocolate and no extra sugar to make it.
The classic metrowiec is filled with pastry cream aka custard buttercream between the slices. My version is better (of course). I use apricot jam spread on the slices, and however strange it sounds to use jam for sharpness and tang, it does add it to the cake in the way crème pâtissière would only add more sickly sweetness.
The sponge and how to make it the easy way
The sponge is very interesting: who ever thought of adding water to cake batter? But it works very well to make light and airy, fluffy sponge that I’m happy to use in other cake contexts.
The classic approach is to separate eggs, beat the whites to stiff peaks then turn it into a meringue by adding sugar bit by bit. That is followed by yolks, the weird water-oil emulsion and finally flour, gently folded.
The orthodox procedure also tells to make each cake separately, the pale and the cocoa-coloured, but life is far too short to wait so long for cake so in the recipe below I’ve taken a shortcut. Make the batter in bulk till the flour addition stage, then divide it in two. Half is finished with cocoa powder and the other half with a little more flour to compensate.
But I have to tell you there is an even better shortcut to it. Provided the eggs are at room temperature, as they should be for baking at all times, you can beat the whole eggs without separating. Which, as I’m aware, is the element most off-putting in cake baking.
A cake or a jigsaw puzzle?
Once the two sponge loaves are baked and cooled, it is a lot like making sandwiches for a school fete: slicing, spreading and stacking. The slices might not want to stay put in which case the back and front will need propping up. Find a board or tray long enough for this (not quite a) metre-long cake and chill it briefly to set.
The glaze is geniusly simple: dark chocolate melted in half the amount of butter. Similar to ganache, it looks more lustrous and it’s easy to spread. Ganache can be used in its place if that’s the preference: chocolate melted with boiling cream in similar proportions as the butter glaze.