Preheat the oven to 200 C / 180 C fan / Gas 6. Grease a 23cm cake tin and line with baking parchment.
In a mixing bowl, cream the butter and sugar together until almost white, pale and soft. Add the eggs in one by one and beat until creamy. Mix in the vanilla extract. Sieve in the flour and baking powder and fold in. Pour the cake mixture into the prepared cake tin.
Bake in the preheated oven for 45 minutes, or until risen and golden and a skewer inserted into the centre comes out clean. Remove from the oven and allow to cool completely before decorating, slicing or serving.
I always put the oven on at the end because there is a risk of it burning. Make sure you don't over mix it or it will not rise. Don't keep opening the oven door or it will sink