01 - In a small saucepan over low heat, combine the ube halaya, water, and condensed milk. Stir until smooth and warmed through, about 2-3 minutes. Remove from heat and mix in vanilla extract.
02 - For a hot latte: Steam or heat the milk until frothy but not boiling. For an iced latte: Use cold milk and fill glasses with ice cubes.
03 - Divide the ube mixture between two mugs or glasses.
04 - Add one shot of espresso (or 1 fluid ounce strong coffee) to each glass.
05 - Pour the steamed (or cold) milk over the espresso and ube mixture. Stir thoroughly to combine and achieve a uniform purple color.
06 - Top with whipped cream and a sprinkle of ube powder or yam flakes, if desired. Serve immediately.