First you need to make chhana /soft paneer from the milk and vinegar. Wash the chhana. Let it stay in the strainer for 15 minutes. For this recipe there is no need to squeeze the whey too much.
Then mash the chhana lightly with a fork. The texture of Kalakand should be grainy, keep that in mind when mashing. Prepare a 9 inch square cake pan by greasing the inside with 1 tbsp ghee.
In a heavy bottom pan, mix the chhana, 2 tbsp ghee, condensed milk, cardamom, and milk powder. After mixing, taste it and check the sweetness. If you wish, at this point you can add the sugar. Now turn on the heat to high and stir for 2-3 minutes then turn the heat to low-medium and stir for 12-13 minutes or until the mixture starts to leave the sides of the pan. The mix should look a little moist; it should not be dry.
Now pour the kalakand into the prepared pan and press gently to get a smooth surface. Let it cool down for an hour. You can garnish with chopped pistachios, cashews, raisins or you can leave it as it is.
Cut it in your desired shape and enjoy!