Place the rice and water in a medium saucepan and bring to a boil over medium-high heat. Reduce the heat to medium and simmer, stirring occasionally, for 20 minutes. Add the milk, sugar, raisins, cashews or pistachios, cardamom seeds, and cinnamon and simmer, stirring often, until the rice is tender and the mixture is creamy, 30 to 35 minutes more. Serve warm or chilled.