(I apologise for the dark photos; I thought I'd take then outside but didn't change the settings nor can I get my photo editor to work. I haven't used the program in a long time so I think it was having trouble importing all my photos.)
The outside of the cake, the cake itself, is a simple biscuit sponge baked in a sheet pan. Rose says it takes 10 min to mix and another 10 to bake and that's pretty much true. The fiddly part comes when you have to make a template of the pieces needed to make the cake shell. One long piece to line the long sides and bottom, two end pieces and a top piece. It was fiddly but not too hard and I decided to save the template (made on binder paper) in the bok justi n case I ever decide to do this again. I cut the cake with a pizza roller (thanks to Marie) and used a pair of scissors to make any final trimming.
The middle, the whole reason you're here, is a creamy and mellow and rich chocolate mousse that starts with dark chocolate and cream. A whole boatlaod of egg yolks are tempered into the hot ganache and cooked until custardy. After the mixture cools a bit, you whip it for a little bit until soft floppy peaks form when the beater is raised. The book says it should take about 30 seconds but for me, it took much more time than that. Then a little one-egg white meringue is folded into the custard to lighten the mix, and then it is time to assemble the cake.
After lining the loaf pan with the cake, the mousse is poured and smoothed into the pan. Everything needs to rest up for 3 hours at room temperature for the custard to firm up, but after cutting into the cake the mouuse was still soft and the cake threatened to fall apart. So if I do this cake again I think I will also refrigerate it for a bit before cutting. i think it would be easier to cut when chilled and then allowed to come up to room temperature before serving.
This would be a wonderful finish to a nice dinner with people you love and a good cup of coffee.