Combine the milk, water, and granulated sugar in a pot and bring to a boil over medium heat. Once the sugar has dissolved, turn off the heat but keep the syrup hot; it will be added to the halva while boiling.

Melt the butter in a wide pan, add the pine nuts and sauté over low heat until they turn pink. The pine nuts brown quickly, so move to the next step as soon as they start to color.

Add the semolina to the pan and toast over low heat, stirring constantly. Caution: Do not raise the heat, or the semolina may burn; stir patiently for about fifteen minutes until the color turns light red and it becomes fragrant.

Lower the heat and carefully pour the boiling syrup over the toasted semolina; the mixture may splatter. Cook, stirring, for a few minutes until the syrup is absorbed.

Turn off the heat, cover the halva with a clean paper towel and a lid, and let it steep for fifteen minutes. Steeping gives it its grainy texture. Portion it out with a spoon and serve hot; optionally sprinkle cinnamon on top.