Place all ingredients except cocoa powder in a large microwavable bowl.
Mix well and place bowl in a microvave oven for 4 minutes on high cook.
Remove bowl and stir mixture. Place again for another 4 minutes.
Transfer half the barfi in a greased plate.
Quickly blend in the cocoa into the remainder and pour over the barfi in the plate and spread evenly.
Cool and cut into diamond shaped pieces.
Blanched nuts can be sprinkled on top along with silver varaq (foil).