Making cashew powder: If you have kept the cashews in refrigerator, take it out and let it dry completely. Powder the dry cashews in a suitable mixer. For this, grind the cashews continuously for a minute till it becomes smooth powder. Do not grind for long time because cashews release oil and it becomes a paste. You can also grind it by using pulse option (i.e grind for few seconds, wipe the sides and repeat until it becomes a powder). After grinding, sieve with a wire mesh if needed. Keep the powder aside.
Cooking cashew dough: In a kadai, heat sugar + water and melt it. Boil till it reaches one string consistency. String should be thin. To this, add the powdered cashews and mix well. It will become watery at first. Keep mixing in medium flame by staying nearby.
Checking consistency: The mixture will thicken and start to leave the sides of pan. At that time, simmer the flame completely. Take a pinch of cashew dough by greasing your fingers. Try to make a soft, smooth ball. If you are able to do it, cashew dough is done. Immediately transfer it to a greased plate.
Kneading cashew dough: Using a spoon, just mix the cashew dough to turn thick and warm. Once its heat is enough to handle, grease your hands with ghee and keep kneading for few minutes. It will turn soft, smooth like a dough ball. Cover the kneaded cashew dough with a dry cloth and set aside.
Making pista dough: Powder the pista to a smooth powder in short pulses without letting it release oil. To the pista powder, add powdered sugar, a drop of green food color and cardamom essence or rose water. Add just a few drops of water and knead into a smooth, non-sticky dough with ghee-greased hands. Divide into 2 parts and roll into thin cylindrical logs.
Rolling and assembling: Place the cashew dough between two parchment sheets and roll thin with a rolling pin into an even circle. Cut the circle into two halves. Place one pista log along the cut edge of the cashew sheet. Fold the cashew layer over the pista log to encase it, then gently roll forward on your work surface until elongated and uniform.
Cutting and shaping: Trim the uneven ends. Slice the roll into small cylindrical pieces using finger width as reference. Gently press each cut roll against the board to shape neat rounded edges. Repeat with the remaining dough. Let the rolls set for 1 hour at room temperature before serving.