Separate egg yolks and egg white. Make sure to keep the egg white in a dry bowl without any trace of water.Remove 2 tablespoon maida from the 100 gm taken and replace it with 2 tablespoon corn flour. This is how we make cake flour. {Cake flour = (100gm - 2 tbsp) maida + 2 tbsp corn flour}Sift together maida-corn flour mix and baking powder 2 - 3 times for uniform mixing. Keep it aside.Grind sugar into a fine powder.Beat egg white using an electric beater until it turns to be a frothy and stiff white mass. When you invert the bowl and if it is not falling down, then it is ready.In another bowl, beat butter, powdered sugar and egg yolks until it reaches a soft, smooth and creamy texture. Add vanilla essence and beat well.To this, add maida mixture and again beat well till it forms a smooth, shiny batter.Cut half the quantity of beaten egg white ( it is stiff enough that you can cut it like a piece of cake) and beat it well with the batter by adding orange juice.Now add the remaining beaten egg white and slowly fold it into the batter using a spatula, till well combined. MAKE SURE TO FOLD IN THE EGG WHITE SLOWLY AND ONLY IN ONE DIRECTION.Transfer the batter slowly into a cake tin either lined with butter / parchment paper or well greased and dusted with maida.Pat the pan gently 2 - 3 time to remove trapped air from the batter.Preheat the oven at 180 degree centigrade for 5 minutes.Keep the cake pan in the pre heated oven and bake for about 20 - 25 minutes or till the skewer inserted in the middle of the cake comes out clean.Remove the pan from the oven and allow it to stand for 10 to 15 minutes.Now slowly unmould the cake and cool it on a wire rack. TIPS:Make sure to keep the separated egg white in a dry bowl without any trace of water.Before beating the egg white, make sure to keep the handle of the electric beater extremely dry. This is very important in beating the egg white into a stiff frothy white mass.If there is any water content in the bowl or the handle of the beater, we cannot beat the egg white into a stiff frothy mass.DON'T USE THE ELECTRIC BEATER WHEN YOU ADD THE 2ND HALF OF THE BEATEN EGG WHITE INTO THE BATTER. FOLD IN THE 2ND PART OF THE BEATEN EGG WHITE INTO THE BATTER USING A SPATULA, THAT TOO ONLY IN ONE DIRECTION.Make sure not to add water while extracting the juice of half of an orange.The baking time may vary depending upon the type of oven. To make a cake using the measurements given here, it will normally take 20 to 25 minutes.This is the recipe of my perfect sponge cake which I derived after experimenting so many recipes. This recipe will give you a super soft sponge cake with a nice texture.