Add milk to a large saucepot and whisk in cinnamon, salt and sugar until thoroughly combined. Bring milk to a gentle boil over medium heat, whisking occasionally. Keep a close eye being careful not to scorch the milk.
Meanwhile, place rice in a mesh strainer and rinse until water comes out clear - about 2 minutes.
When the milk comes to a boil, add rice then simmer on low for 20-25 minutes until liquid is mostly absorbed.
Using a fork, mix cornstarch with a few tablespoons of cold water then add to the pot. Continue cooking the pudding until the mixture begins to thicken - about 1-2 minutes.
Stir in raisins then remove from the heat. Divide pudding evenly between 6 small ramekins or dessert dishes. Serve warm, at room temperature or refrigerate until cold.