Preheat oven to 350 degree F.
Sieve flour, corn starch, baking soda, baking powder and salt, set aside.
In a bowl, cream the butter and sugar until creamy using the electric mixer on low speed. Do not over beat.
Add yogurt and vanilla essence to the butter mix keep mixing on low speed and add the milk slowly. Mix will not be very smooth.
Add the flour few spoons at a time into the batter. Keep folding using the whisk, until all the flour is incorporated in to the butter mix, Do not over beat.
Scoop the batter into baking molds filling them about 2/3 full.
Bake for 20 minutes check the cakes inserting a knife in the center and it should come out clean. It took me 22 minutes.
After cakes come to the room temperature take them out from the molds.