How to Make It
Place rice milk, 1 cup water, almonds, sugar, and 1 1/2 teaspoons cinnamon in a blender; blend 2 minutes or until smooth. Strain mixture through a cheesecloth-lined sieve over a large pitcher; discard solids. Stir in the remaining 1 cup water, and chill for at least 1 hour.
Just before serving, add rum and stir well. Fill glasses with ice; stir horchata, and fill glasses. Dust each drink with a dash of cinnamon.