You can make it at home or purchase paneer, honestly homemade paneer for rasmalai tastes yummy.
Firstly, heat milk and get to a boil.
Once a layer of cream is formed over the milk, stick it to sides of vessel.
Repeat the process for atleast 5 times or till milk reduces to one-third.
Further, add sugar, cardamom powder and saffron milk.
Give a good mix and get to boil.
Also scrape off the collected cream from sides. And give a good stir.
Further, refrigerate for 2-3 hours.