Soak the saffron in warm milk. Let stand.
Take a heavy bottom wide kadai (non stick is better) and add ghee, sugar, milk powder and milk to it. Using a wooden spoon or rubber spatula, mix everything to form a milky slurry.
Place the kadai on low medium heat and begin cooking the mixture. Stir continuously that no lumps are formed and the mixture does not stick to the bottom of the kadai.
After about 5-6 minutes you will see that the milk mixture will start thickening. Continue to cook on low heat with regular stirring. At about 10 minutes, you will see that the mixture starts clumping around the spatula or wooden spoon and you will be able to fold it over itself. Also, t won't stick to the kadai at all.
Add the saffron mix to the mixture and cook for 1-2 minutes, so that the mixture is very well scented with saffron. Don't cook too long else the burfi will be dry.
Take off the stove, wait for 2-3 minutes and while still warm add the burfi mixture on top of the brownie mixture. Using a spatula smoothen and spread it out to have uniform thickness as well as cover the entire surface of the brownie layer.
Once smooth, press down the pistachios on the burfi top. Allow to set for 2-3 hours.
Carefully, lift the brownie out of the baking dish. It will be heavy. Using a sharp knife cut into desired size shape. Enjoy!
Store in fridge upto 5 days.