Preheat over to 180c. Line bases of a 6 hole texas muffin tin with baking paper. Put 2 teaspoons lemon butter in each hole. Top with blueberries.
Using an electric beater, beat butter, sugar and vanilla until light and creamy. Add eggs, 1 at a time, beating well after each addition. Gently fold in flours and remaining lemon butter. Spoon over blueberries.
Bake for 20-25 minutes or until cakes are cooked though when tested with a skewer. Stand cakes for 5 minutes, then turn out onto a baking paper lined cake cooler. Serve warm or cold, drizzled with cream or custard.