Rinse the arborio rice under cold water until the water runs clear.
In a medium saucepan, combine the rice and milk over medium heat.
Add the sugar and salt, stirring until dissolved.
Bring the mixture to a gentle boil, then reduce the heat to low.
Simmer uncovered, stirring occasionally, for about 20 minutes.
Once the rice is tender, stir in the vanilla extract and cinnamon.
If using, add the raisins and butter at this point.
Continue to cook for an additional 5-10 minutes, until creamy.
Remove from heat and let it cool slightly before serving.
Serve warm or chilled, garnished with additional cinnamon if desired.