Well, I think these are definitely the best I've made yet. I took them into work and they got rave reviews, with one colleague saying they were possibly the best coffee walnut cake she had eaten! Can't ask for better than that really. It's just a shame that I'll never taste them I suppose!!! (Nut allergy and not liking coffee very much.) I try not to work with nuts too often, but I had a packet of walnuts in the cupboard destined for a rich fruit cake that I'd changed my mind about making, so it was a good use to put them to. J has often found when making cakes for Church coffee mornings that the coffee walnut is one of the first to sell out, it just seems to be very popular. It could also be that she bakes a fantastic coffee walnut cake, all of the regular coffee morning attendees know this and it gets snapped up in the blink of an eye. Personally I think it must partly be a nostalgia thing, nothing says hazy summer childhood days better than coffee walnut cake.
I've made this before as a traybake type cake (as J does) and sliced it up before serving, but individual cakes are easier for work and lend themselves to piped buttercream better than a large cake does. However, I noticed that the texture of this cake is extremely light and fluffy, more so than you would expect for a normal sponge cake mixture. I don't really understand why this is, as it's made in the same way so I'm guessing it's something chemical to do with the coffee in the cake mix. Interesting....
So, onto the recipe. Quantities are a little flexible - it depends how much you like coffee and walnuts! I used 50g of chopped walnuts in the mixture, but you could easily increase that, perhaps even double it if you want to. I used a heaped tsp of instant coffee dissolved in about a tbsp of boiling water for the mixture, but again, if you're a coffee fiend and like your coffee mega powerful, you could try a tbsp of coffee in the least amount of water it takes to dissolve it. The buttercream is also a moveable feast - I was making buttercream for two different sets of cakes at the same time, so at a guess I used 100g of butter to 225g icing sugar and a heaped tsp of instant coffee in a tbsp boiling water. If you love buttercream and want all your cakes to look like the ones on the right hand side of the picture above (no cake visible, buttercream right to the edges of the case) I'd say to use 120g butter to 260g icing sugar, plus coffee. Otherwise 100g butter is probably fine. So, the recipe....
Coffee Walnut Cupcakes with Coffee Buttercream Icing
120g butter, softened
60g caster sugar
60g light muscovado (light brown soft) sugar
2 large eggs
120g sifted self raising flour
1tsp instant coffee dissolved in 1tbsp boiling water (or more, see above) - allow to cool
50g chopped walnuts
For the icing
100-120g softened butter
225-260g icing sugar, sifted if very lumpy
1 heaped tsp instant coffee dissolved in 1tbsp boiling water (or more, see above), allowed to cool
12 walnut halves
-Preheat the oven to 180C/Gas 4. Line a 12 hole muffin tin with paper cases.
-Cream butter and sugars together until light and fluffy.
-Add eggs one at a time with a little flour to stop the mixture curdling if you want.
-Add the cooled coffee mixture. It does seem a pain to wait until it cools, but if you don't it's likely to curdle your mixture (as I found to my cost - I actually added mine after the flour, having forgotten to add it before, and it split the mixture a little, but luckily the final cakes were ok!)
-Fold in the flour and chopped walnuts. Divide the mixture between the paper cases and bake for 20-25 minutes until springy when pressed and a cake tester/cocktail stick comes out clean. Remove to a wire rack and allow to cool. (Drool as the smell of coffee and nuts fills your house....)
-For the buttercream, combine the softened butter and icing sugar with a fork, then switch to an electric mixer and carry on beating until the buttercream is very light and fluffy and has turned pale in colour. Add the (cooled) coffee mixture (to taste - see above) and beat to combine.
-Place the nozzle of your choice into a piping bag, fill with the buttercream and pipe away to your hearts content. Swirly buttercream - yum.
-Place a walnut half (try and find 12 nice halves in the packet of walnuts - this is one case where you do need to buy the more expensive halves rather than chopped/broken walnuts) on the top of each little tower of buttercream. You could add some more chopped walnuts on the side of the buttercream, but I prefer the simplicity of just the one half on top.
-Enjoy your creation. (Or in my case, give your creations to someone else and watch them enjoy!!!)
Chopped walnuts ready to be added to the mixture - you can just see the halves I've reserved for topping the cupcakes to the left of the picture.Strong, strong coffee. Even J doesn't drink it like this! Notice the resemblance to tar!!! You want the instant coffee to only just dissolve in the boiling water.