01 -
Combine brown sugar, water, vanilla, and salt in a small saucepan over medium-low heat. Stir for 2-3 minutes until the sugar dissolves, then let the syrup cool briefly.
02 -
Sift the matcha into a small bowl or measuring cup to remove dry lumps.
03 -
Add the warm water and whisk in quick zigzags for 20-30 seconds until smooth, glossy, and lightly foamy.
04 -
Spoon the brown sugar syrup into a tall glass. Add the ice, then pour in the cold oat milk.
05 -
Slowly pour the whisked matcha over the milk. Add cinnamon if using, then stir before drinking.