Shake with ice and strain into a chilled collins glass filled with crushed ice. Garnish with mint sprig and pineapple leaves.
For the ube milk, I used a blender to mix together 8 oz of ube puree, 1.5 cups water, 1 cup unsweetened coconut milk, 1 cup sugar, 4.5 oz condensed milk, and 1.5 tsp ube extract.