Pre-heat the oven to 175°C (350ºF). Grease and line an 20cm (8") springform cake tin.
Cream the butter and sugar and beat in the eggs one at a time.
Add the elderflower cordial, oil, vanilla extract, and yoghurt and beat until smooth.
Sift the flour, baking soda and baking powder together and add to the wet ingredients, stirring just until incorporated.
Pour into the prepared cake tin and bake for around 30-35 minutes in the lower part of the oven, until an inserted skewer comes out clean.
Leave to cool in the tin for 5 minutes then poke all over with a skewer to create tiny holes.