In a large saucepan, combine the milk, sugar, vanilla extract, cinnamon, and salt. Bring to a gentle boil over medium heat.
Stir in the Arborio rice. Reduce the heat to low and simmer, stirring frequently, until the rice is tender and the mixture is thickened, about 40 minutes.
If using, stir in raisins, nuts, or chocolate chips during the last 5 minutes of cooking.
Remove from heat and let cool slightly before serving. The pudding will thicken as it cools.