Preheat the oven to 160 C. Put the butter, sugar, eggs, yoghurt, lemonzest and vanilla in a bowl and mix to combine
Add the flour and mix everything well. Fold the blueberries through the batter and pour into a caketin of about 22 x 8 x 7 cm which is covered in baking paper/
Smooth the surface with a spatula and bake the cake for about an hour or until it is cooked through. Test this with a wooden stick in the middle of the cake. If it comes out dry your cake is done.
Leave the cake to cool for ten minutes in the tin before turning it over onto a cake rack to cool completely.
Before serving dust with icing sugar and serve with some extra blueberries