In a large bowl, combine the rinsed rice and water. Let it soak for at least 3 hours or overnight.

Drain the rice and add it to a blender with 4 cups of fresh water. Blend until smooth.

Strain the blended mixture through a fine mesh strainer or cheesecloth into a pitcher, discarding the solids.

Stir in the milk, sugar, vanilla extract, ground cinnamon, and salt until well combined.

Refrigerate for at least 1 hour before serving. Serve over ice and garnish with additional cinnamon if desired.