Begin by boiling water until it reaches a bubbling temperature, around 200°F. In a heatproof container, steep the dried butterfly pea flowers in hot water for 5–7 minutes until the water transforms into a deep blue hue. Strain the tea to remove the flowers and allow it to cool slightly.

While the tea cools, prepare the creamy topping. In a blender, combine ice-cold milk with vanilla syrup. Blend for about 10 seconds until smooth and frothy.

Take a tall glass and fill it with ice cubes. Pour the cooled blue tea over the ice, watching as the vibrant color fills the glass. Ladle the creamy vanilla foam over the top.

You can present with distinct layers or stir to blend the foam and tea. Add a squeeze of lemon or lime if desired.