Soak rice in water for at least an hour.
Add all remaining ingredients, except 1 cup water and cashews, cover, and bring to a boil over medium heat.
Lower heat, cover, and let cook at a low simmer for 45 minutes, stirring occasionally.
Meanwhile, blend 1 cup water and cashews in a blender until completely smooth.
Whisk into rice mixture.
Let sit for 10 minutes.
Remove cinnamon sticks, ginger, cloves, and cardamom pods.
Serve warm or cold and sprinkle with cinnamon, if desired.