My friend Swati Palekar introduced me to this lovely but very simple to make cake. I used the zest of green lemons and was delighted when the entire sugar turned green with the aroma of lemon filling the kitchen...This is a lovely cake to ave for tea time. I again baked this with wheat flour and so substituted the 2 tspns of baking powder with 1 tspn of baking powder and baking soda each. I also doubled the vanilla essence to mask the smell of wheat flour. If one uses wheat flour one needs to beat a little more than what one would while using all purpose flour.
The link to the original recipe. Do read carefully all the recommendations given by the author.