Line your cupcake tray with liners. Preheat your oven to 170 degree centigrade.
In a large mixing bowl combine flour, salt, corn flour, baking powder and baking soda. Sift this 2-3 times. Divide into two parts.
To one part add 3 tablespoons oil, 105 grams caster sugar, 1/4 cup curd/buttermilk and 1/2 teaspoon vanilla essence. Make a smooth and thick batter using 1/3 cup water. The vanilla batter is ready.
Make the chocolate batter with the second half by adding all the ingredients for vanilla plus the cocoa powder.
Pour 1 teaspoon vanilla batter into cupcake mold. Pour a teaspoon of chocolate batter on top of it. Repeat this until you fill half the liner. Do not fill more than 1/2 the height.
Bake at 170 degree centigrade for 18 minutes or until done. Once done, cool them to room temperature.
To a cup of icing sugar, add light corn syrup, a few drops of vanilla essence and 3-4 teaspoon water. Mix well. Make a smooth and thick but pouring icing. Add more water if needed. Add pink food color and decorate your cupcakes using this.