Soak the pistachio in enough hot water for at least one hour.
Drain out the water. Remove the skin from the soaked pistachio.
Add the pistachio to a food processor and process to a paste. Don't overprocess as you don't want a nut butter.
Heat the measured water, orange zest and sugar in a pan over medium heat. Stir so that the sugar melts.
Allow the mixture to simmer till you get a one string consistency syrup. I usually press a bit of the cooled down syrup between my thumb and finger and open. If an unbreakable string is formed then the syrup is ready.
Once the syrup is ready, add the orange blossom water and mix well.
Then add the pistachio paste. The mixture will be runny.
Keep stirring it using a spatula till the mixture comes away from the pan and forms into a dough. This process takes about 7-10 minutes.
Take a small ball of the mixture. Allow it to cool and try it roll it into a ball. It should not stick to your hand or fingers.
If it doesn't stick then the mixture is ready. Allow it to cool down just enough till its comfortable to handle.
Grease small molds with some unsalted butter or ghee.
Take about a teaspoonful of the barfi fudge, roll it into a ball.
Put the ball in the mold, press it gently down and to the sides of the mould. Make sure the depression is enough to hold some phirni in it. I used silicon molds.
Occasionally grease your finger tips to make the shaping process easier.
Allow the pistachio fudge cups to set completely for at least 6-8 hours. I left mine overnight.
Once set carefully remove the pistachio fudge cups from the molds.