Don't substitute the espresso coffee for instant - you won't sleep for days - and it won't taste as it should. Use a domestic espresso machine or stovetop pot to make a batch and cool before using.
Recipe makes a 20cm cake to serve 8 - 10 people.
250g butter, softened
220g caster sugar
1 tsp vanilla extract
180ml espresso coffee, cooled
2 tsp baking powder
180g butter, at room temperature
240g icing sugar
40ml espresso coffee
1 tbs Kahlua (optional)
40g toasted almond flakes
Preheat your oven to 170C for fan ovens, 180C for conventional oven.
Spray a 20cm cake tin with oil and line with baking paper.
Sift flour and baking powder into a bowl (it's easier to do it a head of time).
Using a paddle attachment, ideally on a stand mixer, cream the butter and cream together, It will be ready when it is pale in colour, and fluffy. If it's still yellow, it's not time to proceed. You can use medium to high speed on your mixer.
Add the eggs, one at a time, until fully incorporated, on medium speed.
Start to add the coffee into the mix, with the mixer on low speed, using a small jug is a good idea. Don't worry if your mix curdles - it will, with that much coffee in it. You are going to add the flour and baking powder mix anyway.
Fold the flour mixture into the batter with a spatula. Using your mixer could lead you to over mix and make the cake tough. Once you have a smooth, even mix, pop into the tin, smoothing the top, and bake for 30 - 40 minutes. Check with a skewer to make sure it's cooked through - you don't want it to sink!
If you want a larger cake, add 1/4 extra of each ingredient for a 23cm cake to serve 10 - 12 people - or double for a 28cm cake.
For the icing, cream the butter and icing sugar until smooth, slowly add the espresso coffee and Kahlua.
Once the cake is very cool, use a bread knife to cut across the middle of the cake. Add about a third of the icing onto the bottom layer. Add the top layer, and ice with the remaining buttercream. Sprinkle the toasted almonds around the edge of the cake. You can also ice the sides. Use an offset spatula for best results.