Preheat oven to 180 degree Celsius (160 Celsius for fan-forced oven).

Whisk the eggs very lightly. Add in butter, yogurt, and vanilla essence to the beaten egg. Whisk again. Set aside.

Sift in plain flour, caster sugar, baking powder to another deep bowl. Mix well.

Now make a well in the center of the flour mixture, and pour the egg mixture in it.

Use a wooden spoon to gently combine the ingredients without forming any lumps. Remember no over mixing.

Finally, stir in the blueberries. Set aside.

Meanwhile, grease a round 22" cake tin with cooking spray.

Spoon mixture into the cake tin.

Bake for about 1 hour. A skewer inserted into the center of the teacake should come out clean. Once done, take it out of the oven, and leave to stand for 5 minutes. Then, transfer to a wire rack to cool.

Dust with icing sugar, if desired. Serve.