01 - Set oven to 325°F. Lightly grease a 2-quart baking dish with butter.
02 - Rinse rice under cold water until water runs clear. Drain well.
03 - In a large bowl, whisk together condensed milk, whole milk, melted butter, granulated sugar, vanilla extract, ground cinnamon, and salt.
04 - Stir in the rinsed rice and raisins, if using.
05 - Pour the mixture into the prepared baking dish and gently stir to evenly distribute the rice.
06 - Bake uncovered for 1 hour, stirring gently every 20 minutes, until set and the top is lightly golden.
07 - Remove from the oven and allow pudding to cool slightly. Serve warm or chilled, sprinkled with extra cinnamon if desired.