Using a mixing bowl , stir together the flour , cocoa, cornstarch, baking powder and salt. Keep aside.

In another bowl beat sugar and butter till creamy .

Add vinegar , vanilla essence, egg replacer, water, food color . Beat well .

Stir in the flour mix into the wet mix , stir in half the chocolate chips and retain the rest .

Refrigerate the dough for an hour .

Preheat the oven at 180deg C for 15 minutes

On a lightly greased cookie sheet scoop out about a tablespoon of dough for each cookie and slightly flatten it .

Place them at a distance of 2-3 " as these cookies will spread .

Bake for 9-10 minutes .

Remove from the cookie sheet and place it on the wire rack to cool.

While the cookie is still warm press in the white chocolate chips in s neat pattern .

Once cool , store in a airtight container .