I've made myself a coffee & walnut cake with the intention of eating the whole thing on my own and not sharing it with anybody to prepare myself for the inevitable cravings that lent brings.
I've made the sponge plenty of times but the icing was from the Great British Book of Baking and uses cream, icing sugar, melted and slightly browned butter and coffee essence. Its nice and nowhere near as sweet as some I've had so it works well with the cake.
I didn't use instant coffee as a flavouring this time though, I used Camp coffee essence and I'm sure its changed the way the cake and icing taste. Its still nice though, I just have to stop myself eating it until Tuesday (pancake day when I plan to eat a LOT.....).