Notes: My original plan was to make Nigella Lawson's Chocolate Malteser Cake but many reviews online have mentioned it's not very tasty, so I tried this more complicated cake. Do read the directions carefully, as numerous eggs are required in the cake layers and mousse, and you don't want to make the chocolate genoise twice (like I did). Add all 9 egg yolks to the mixer after scooping out the egg whites (the directions aren't clear about this point). The genoise was very moist and soft, sticking to the plastic wrap and my hands and broke apart during assembly. Making the mousse using gelatin sheets was a snap. To avoid lumps, I stirred the Horlicks powder into the sugar before adding it to the milk.
Following the directions will clearly not produce a cake with three layers of mousse, unlike the accompanying photo. That's one of the problems with The Sweet Spot, it suffers from poor editing and proofreading. The index is woefully sparse too. Anyway, back to the cake: I trimmed the cake to about 7" on a side to allow the mousse to completely cover the cake but in retrospect, this was unnecessary as I ended up trimming the edges of the assembled cake anyway to allow the layers to show. The buttercream was problematic, as the large amount of coffee was difficult to combine into the butter using a handmixer. I switched to a mini-food processor which was of no help before trying again with the handmixer. It eventually came together but did weep considerably. I would reduce the amount of liquid by half next time, or use coffee liqueur instead. For so much effort, this cake was definitely worth it. Super moist layers of chocolatey cake combined with a well-balanced chocolate-malt mousse equals delicious!