Heat 1 tbsp milk and add saffron threads, few drops of yellow food color to it. Grease a pan with ghee & grease a flat bottomed bowl with ghee for levelling the dough. Keep it ready. Refer picture below for the idea.
In a small non-stick kadai , pour the saffron milk and set aside. We need it for later use.
Heat unmelted butter in another big non-stick kadai in low flame. When its melting, add the milk. Mix well. When the milk and butter are mixed well, add the milk powder and stir it without lumps. Milk powder will absorb all the milk & butter and it looks like a thick paste/ khoya.Stir the mixture to become smooth.
Now add the powdered sugar and stir well. Sugar gets melted and the paste becomes thin. Keep mixing in low to medium flame. Never increase the flame and do not go away. Stay nearby and keep mixing else the bottom layer gets burnt very quickly. Add the rose water or cardamom powder and keep mixing for 5-6 minutes. The burfi mixture starts to thicken and leaves the sides of kadai.
When it starts to leaves the sides and becomes semi thick, take a small portion in plate. It will be very sticky. Grease your fingers with ghee and try to make a ball out of it. If you are able to do make a soft, non sticky ball, its the right consistency. Immediately switch off the flame and stir for few seconds. The heat of kadai is sufficient to thicken the burfi mixture.Mixture will be very sticky and tastes slightly chewy too. But don’t worry.
Remove 1/3rd portion of burfi mixture using a ladle and add it to the kesar milk we kept in the kadai earlier. Transfer the remaining mixture to the greased plate, it will fall like a ribbon. Spread it well with the bottom of greased bowl. Let it cool down.
In my burfi, two layers were not clearly visible. So its better to add the yellow layer less than half the quantity of white layer.
Now take the dough mixed with kesar milk. Keep mixing till all the milk is absorbed by the burfi dough and its color changes to yellow. If you wish, add more yellow color if needed. Switch on the flame and mix it for one minute in very low flame. This is to absorb the extra moisture in the burfi. Transfer it to the greased tray and spread it over the plain white layer. Use the greased bowl and spread it well to cover the white layer. Set it to become warm for 2-3 hours.
Grease a knife with ghee and make shapes once the mixture becomes warm. Do not remove the pieces now.This burfi tastes chewy if consumed hot. So Let it rest over night or at least 8 hours by covering with a plastic sheet. The next day, run a knife in the corners and invert the plate. All the pieces will fall easily. Remove and stack it. Store in a box and enjoy for a week. No need to refrigerate. Melt in mouth kesar burfi with milk powder is ready !