Preheat oven to 180°C. Grease and line a 20cm ring
tin with baking paper. Using an electric hand
mixer, beat butter and sugar until light and
creamy. Add eggs, 1 at a time, beating well after
each addition. Sift flour over batter. Add yoghurt
and blueberries. Using a large metal spoon, gently
stir until well combined.