Chocolate-Coffee layer cake with Coffee Buttercream

How fitting that I went to visit some dear friends on International Coffee Day two Sundays ago on 1 October knowing that one of them is a coffee addict!

As so often I baked the tasty, fail-proof and versatile German wonder cake using 200 ml of coffee and replacing 50 g of flour with 50 g of cocoa. It is such a great recipe and baked the day before it is excellent to use for layer cakes the next day. All the mixture fitted perfectly into a 24 cm round baking tin and I was able to cut it into 3 layers. Click here for the cake recipe.

German buttercream is different than American/British buttercream in that besides butter the basis is a pudding. Classic flavours are vanilla or chocolate but really you can make any flavour you wish. I made coffee pudding using 400 ml coffee and 100 ml milk.

Basic pudding ingredients
500 ml milk (660 ml)
90 g sugar (135 g)
45 g cornflour (60 g) – I sieve mine to prevent lumps
3 egg yolks (4 egg yolks)
1 tsp vanilla extract
a pinch of salt

This amount if sufficient for lower cakes 24-26 cm in diameter. If you are making a very high cake and you want to decorate it with buttercream on the outside as well, then use the amounts in the brackets.

Most recipes call for egg yolks, but I hardly never use them. When making a vanilla pudding the yolks do of course give it a nice colour. But then you are left with egg whites which – if you have time – you could use to make meringues, but for me, the pudding works perfectly without eggs. The cornflour thickens the pudding very well and so far I haven’t noticed the lack of egg yolks. I might add one for the colour (for vanilla) but that’s it 🙂

To prepare the pudding, pour about a third of the milk and all the other ingredients into a pan and stir with a whisk until well combined. Add the remaining milk and gently turn up the heat continuously stirring the mixture. The pudding will start to thicken quite quickly once the milk warms up, keep stirring with a whisk. Don’t let the pudding boil as it will burn. Just beat a few times as it thickens and begins to bubble and then remove from the heat. Pour it into a separate dish and cover with greaseproof paper placing it right down onto the pudding to prevent it from forming a skin.

Making the buttercream
In addition to the pudding, you’ll need 320g butter at room temperature (420g if you are making the larger amount)

Beat the butter in a stand mixer on medium speed with a paddle attachment for about 5 minutes until it is light and fluffy. Some recipes call for passing the pudding through a fine sieve to get rid of any lumps. I don’t bother as sieving my cornstarch has so far left me with no-lump puddings.

With the mixer running on a low-speed spoon in the pudding one spoon at a time leaving enough time for pudding and butter to blend. It is very important that the pudding and the butter both have room temperature. If you make the pudding the day before (which is fine) then take it out of the fridge a few hours before preparing the buttercream. If making on the same day then make sure it has really cooled down.
Should your buttercream curdle then you can save it by placing it over a warm water basin, stirring the mixture with a whisk until it comes back together again. If your pudding was too warm then placing the buttercream in the fridge for 5 minutes should help and then beat it well.

Assembling the cake
I brushed each layer with some sweetened black coffee and split the buttercream between the layers leaving a little to just about crumb coat the cake (at the sides).

As I had wanted to try out the decorating technique with the blobs for ages I had made some ganache using 400 ml cream and 400 g dark chocolate, whipped it and then applied three horizontal blobs as you can see on the photo.

Enjoy baking (and eating) this cake! 

Buttercream recipe originally from Sally’s Blog: