In a large saucepan, bring water to boil. Stir in long-grain white rice and salt. Cover and reduce heat to low. Simmer, stirring occasionally, until water is mostly absorbed, about 15 to 20 minutes.
Microwave milk until steaming (140 to 160 degrees), about 1 to 2 minutes. To the rice, stir in milk and granulated sugar and bring to a slow simmer.
Cook, uncovered and stirring occasionally until mixture is thick, about 45 minutes (a spoon should be able to stand up in the pudding).
Remove from heat and stir in vanilla extract. Allow pudding to cool slightly before serving, or refrigerate until chilled to serve cold, about 2 hours. Dust with ground cinnamon.