Wash the Basmati in cold water 6 times till the milky water begins to run clear and soak for 1 hour;
In the meanwhile, take 1 tsp of the saffron threads and crush with a pestle & mortar or back of a spoon in a small bowl;
To this mixture, add ½ tsp of whole threads and 1 tbsp of warm water. Set aside;
Add the Basmati to a pot with 4 cups of cold water on the lowest heat;
Let the Basmati simmer for 30 minutes till you see it has cooked and moistened and the water has almost evaporated;
To the moistened rice, add sugar mixed in hot water, rose water, butter, a cinnamon stick, almonds, cardamom seeds and the saffron infused liquid and stir gently;
Cover and let cook for another 20 minutes;
You will have to stir it occasionally, but gently, to ensure the rice is not sticking to the bottom of the pot;
Uncover the lid and cook for another 20 minutes;
Remove and discard the cinnamon stick and ladle pudding into 4 individual cups;
Refrigerate for at least 2 hours or overnight;
Serve with a sprinkling of powdered cinnamon and slivers of pistachios.