1. In a 1-quart enameled or stainless-steel saucepan, combine 1½ cups of the milk with the sugar and, stirring constantly, cook over moderate heat until the sugar dissolves.
2. Stir the cornstarch into the remaining milk, then pour into the milk-and-sugar mixture. Bring to a boil and cook until the mixture thickens to a custard like consistency. Set aside off the heat.
3. Preheat the oven to 350°. In a mixing bowl, combine the walnuts with the melted butter and toss them with a wooden spoon until they are completely coated.
4. Then spread them out in a shallow, heavy pan just large enough to ho\d them in one layer. Toast them in the oven for about 20 minutes turning them frequently with a large spoon until they are a deep brown.
5. Watch carefully for any sign of burning. Pour the custard evenly over the nuts, cover the pan securely with foil, and bake in the upper third of the oven 15 or 20 minutes, or until the custard is thick and syrupy.
6. Transfer to small bowls or plates, sprinkle with cinnamon, and serve at once.
