The cake took about an hour to make and bake and the icing took about 10 minutes, however you need time in between for the cake to cool. According to the recipe the cake feeds about 8 people however we managed to cut it into 16 slices so it depends on how hungry you are.
Ingredients for a 20 cm chocolate cake:
3 tbsp cocoa powder
125g plain white flour
2 tsp baking powder
150g butter, softened and cubed, plus extra for greasing
150g caster sugar
25g light muscovado sugar
3 eggs, lightly beaten
1 tsp vanilla extract
A pinch of salt
900g icing sugar, sifted
300g unsalted butter at room temperature
120g cocoa powder, sifted
120ml whole milk
I forgot to put the baking powder in the original photo!!
Preheat the oven to 190 C / 170 C fan / gas mark 5. Lightly grease a 20cm round loose-bottomed cake tin with butter and line with baking parchment.
Sift the cocoa powder into a large bowl, add 3 tablespoons of warm water and whisk until smooth. This was easier said than done for me - my result was not very smooth and was quite "bitty" even though I whisked for about 3-4 minutes.
Scrape the batter into the prepared tin and bake for 35-40 minutes - you can check whether it is ready or not by inserting a skewer into the middle and if it is cooked through, it will come out clean.
When it is ready, leave to cool in the tin for 5-10 minutes and then transfer to a wire rack to cool completely. Once cool, slice the cake in half horizontally using a serrated knife.
While the cake is cooling, you can make the frosting. As I said, I used a Hummingbird Bakery recipe for this - my ultimate favourite. I was on the phone to my brother when I did this so I didn't concentrate and added the milk too early - thankfully it didn't matter - however here is how to do it properly!
Sift the icing sugar and cocoa powder into a bowl. Then beat together with the butter using an electric whisk on a medium speed until the ingredients come together and are well mixed. I made a right old mess doing this - cocoa powder was literally flying everywhere!!
Finally, spread the frosting on the top of one half of the sponges, put the other sponge on top of this and cover the rest of the cake (top and sides) with the remainder of the frosting. I managed to actually break the cake as I did this but thankfully covered it up with the icing!
Finally decorate as you like - with haribo, marshmallows, maltesers, smarties or Harry Potter edible wafer papers like us. My only advice it decorate when the frosting is still very fresh as it then sticks better.