This kid-friendly horchata is garnished with a cinnamon puff of Spin-Spun's organic, dye-free flavored cotton candy. For a grown-up version, stir in 1/2 cup dark or light rum after straining.
In a medium saucepan over medium heat, bring whole milk and cinnamon stick to a simmer. Remove from heat and transfer to a bowl. Whisk in condensed milk, flour, and vanilla. Refrigerate for at least 30 minutes.
Strain mixture through a fine-mesh sieve. Divide among 4 ice-filled highball glasses.