How to make chocolate sponge cake

This chocolate sponge cake is a great recipe for afternoon tea or any time. I love chocolate cake and this is one of my favourite recipes.

Preheat oven to 150 Celsius, line two 8 inch/20 cm round cake tins and put them to one side.
Put the butter, sugar and vegetable oil in a bowl and whisk it together until creamy and light coloured.
Start adding the eggs one at a time and whisk well between each egg added.
Add in the flour, baking powder (if using) and cocoa powder, and fold in the mixture until smooth.
Divide the mixture between the two cake tins and use a knife to level the top with a knife.
Bake in the oven for about 30 – 35 mins until light and golden brown, test with a toothpick and if it comes out clean they are ready.
While they are baking make some chocolate buttercream and add some coffee extract or powdered coffee to it
Leave them in the cake tins for about 10 minutes and then remove them and put them on the cooling rack to cool completely.
When they are ready put one on a serving plate and pipe or spread some of the chocolate buttercream on it.
Put the second cake on top and sieve some icing sugar on top. If you want to pipe more icing on top you can leave out the icing sugar and pipe more buttercream. (Make more chocolate buttercream if you need to)
Serve and enjoy.