Beat egg whites until stiff.
Mix flour, baking powder and cardamom, sieve it and keep it aside.
Mix sugar and oil in pan and beat it.
Now add egg yolks and beat it.
Then put half flour mixture and yogurt and beat it.
Now put more flour mixture and yogurt, beat it, fold egg whites and mix it.
Now take out batter in 8x8 inch square tin, put topping ingredients and bake on 180 degrees for 40 minutes