The December We Should Cocoa challenge is being hosted by Choclette of Chocolate Log Blog and she's chosen dates as the ingredient to combine with chocolate. I use dates in some cakes but not usually with chocolate and I wasn't sure what to do until my good lady wife suggested a Gâteau Breton. Although this gateau is very often plain, some people prefer it with a filling such as apples or prunes soaked in armagnac. So I put together a date and chocolate filling instead, which may look unpromising (or even faintly disgusting) but I assure you it tastes good. You don't even have to buy expensive whole dates for this – simple chopped dates will do fine, as long as they're nice ones. Actually, we did buy some whole dates, but then we ate them.
There are a lot of rules about how the authentic Gâteau Breton should be made and I don't seem to stick to all of them; but then neither do all the apparently authoritative recipes I've seen. Two rules I do stick to, though, are that there should always be the same weight of sugar as butter and that the butter has to be salted. I'm reliably informed that using unsalted butter in a Gâteau Breton would be one of the worst thing you could do in Brittany – roughly the equivalent of walking into a bar in Quimper and announcing that you don't like bagpipes.
You could make the filling the day before and keep it in the fridge until needed. Bring it back to room temperature before using, though.
For the filling:
100 g chopped dates
140 ml water
1 tbsp dark rum
1 tbsp dark brown soft sugar
a knob of butter
20 g plain chocolate, broken into small pieces
For the gateau:
225 g salted butter, softened and cut into pieces
225 g golden caster sugar
300 g plain flour, sieved
1 tbsp calvados (not essential but I add it for luck)
5 egg yolks
1 egg white
First, make the filling. Put the dates, water, rum and sugar in a saucepan and heat gently with plenty of stirring until the mixture starts to look like a paste (a spoon dragged through it should leave a clear trail on the bottom of the pan). Take off the heat and stir in the butter and chocolate. Keep stirring until both have dissolved. Set aside to cool.
Preheat the oven to 180ºC. Thoroughly grease a 20 cm cake tin (it needs to be about 5 cm deep). If you happen to have a mixer with a paddle attachment standing round doing nothing then it will make the following gateau-beating process a lot easier.
Cream the butter and sugar thoroughly. Lightly beat the egg yolks, remove a scant tablespoonful and set this aside for glazing the top of the gateau. Add half of the remaining egg yolks to the butter and sugar and beat in, then do the same with the other half of the yolks and the calvados. Finally add the flour and beat in until everything looks nice and smooth.
Put half of the mixture into the prepared tin and spread it out as flat as reasonably possible – a combination of a palette knife and fingers works best for me. Spread the filling over the mixture evenly but avoid going right up to the edges. Cover with the other half of the mixture making the top as flat and smooth as possible. Lightly beat the egg white and paint over the top of the gateau – you probably won't need it all. Now paint with the reserved egg yolk – add a tiny amount of water if the yolk is too thick to spread. At this point, it's traditional to mark the top of the gateau with a pattern using the tines of a fork.
Bake for 40 – 45 minutes – the top should be a deep golden brown. Allow to cool a fair bit before removing carefully from the tin. Quite small slices are probably the order of the day – this is pretty rich.