Spray a 2-quart slow cooker with vegetable oil. Add all the ingredients except the cinnamon sugar and stir.
Cover and cook on low for 4 hours. Stir the mixture a couple of times during the cooking.
Transfer to a small baking dish and sprinkle with cinnamon sugar.
Notes
Most of us have long grain rice handy, however using a short-grain rice like Arborio will provide an even creamier pudding. Long-grain rice can be used but will yield a less creamy result.Even though one of the benefits of a slow cooker is the "set it and forget it" approach, stirring a couple of times ensures an even, creamy texture.Slow and low is the best approach for rice pudding in a slow cooker. The rice will absorb the liquid slowly and become tender without burning.After you've turned off the heat, give your pudding some time to rest and thicken before serving. It will continue to absorb liquid and set as it cools.Add a little more milk toward the end if you want a thinner rice pudding.