If using rum, soak raisins in it, or simply pour ½ cup of hot water of them, and let rest for 30 minutes.
Grind farmers cheese through a meat grinder and mix it with sour cream until the mixture reaches consistency. Mix in the confectioner’s sugar and raisins.
Place a cheese cloth over the mold and fill it with the farmers cheese mixture.
Cover with a wet cloth and place a weight over it. Place the mold on a plate, to catch the whey, and leave in the fridge for 12-24 hours.
If you have no mold, form a ball and wrap it tightly in a double-folded cheese cloth, place it on a plate, and refrigerate for 12-24 hours.
Carefully remove the Pakha from the mold (or cheese cloth) and sprinkle with some walnuts.