It is called as खुवा or कुरौनी in our Nepali language. And it is popularly sold by dairy shops or factories and by farmers. I don't know how this is prepared as it was brought to me by one of my relatives whose occupation is farmer and he lives in the village area. But it is made by drying up milk until the solid residues of milk remains in the vessel with no moisture. It is used to make variety of sweets including Barfi, Lassi. But I know Indian has variety of products made from it than Nepal and other south Asian nations.
I just tried eating this Khoa by putting walnut, cashew nuts and black raisins to add more flavour. You simply can't hate this. You can find Khoa whenever you visit any dairy shop in Nepal.