Start with 1 litre of full-fat milk in a wide, heavy-bottomed pan. Add a splash of water to prevent scorching and bring it to a boil.
Turn the flame to high. Gradually add lemon juice—about 1/8 teaspoon at a time—mixing well and cooking for a minute between additions. Continue until the milk curdles and turns grainy. (We used around 1 tsp, but adjust based on your milk.)
Lower the flame to medium. Add ¼ cup sugar and 1 tablespoon ghee. Cook until the mixture resembles palgova (a soft milk fudge).
Add another ¼ cup sugar and 1 tablespoon ghee. Stir and cook until the mixture thickens and begins to leave the sides of the pan.
Add 1 tablespoon jaggery and cook until the mixture forms a cohesive mass.
Transfer to a tray lined with greased parchment paper. Level with a greased knife. Cover with another sheet of parchment, seal, and wrap with two soft towels. Let it rest undisturbed for 5 hours.
Carefully unwrap and unmold. Cut into desired shapes using a sharp, greased knife. Enjoy your homemade milk cake!