01 - In a saucepan, combine mashed ube, granulated sugar, coconut milk, ube extract, and a pinch of salt. Cook over medium heat, stirring constantly, until the mixture is smooth and slightly thickened, approximately 5 minutes. Remove from heat and allow to cool to room temperature.
02 - In a blender, process unsalted shelled pistachios, whole milk, heavy cream, honey or sugar, vanilla extract, and a pinch of salt until smooth. Transfer to a saucepan and gently heat over medium-low, stirring often, for 5 minutes without boiling. Remove from heat and let the mixture cool.
03 - Pour the cooled ube mixture evenly into ice cream bar molds, filling each mold halfway. Place in the freezer for 1 hour or until firm enough to add the next layer.
04 - Top the set ube base with the cooled pistachio mixture, filling molds to the top. Insert sticks and freeze for a minimum of 5 hours, or until the bars are completely solid.
05 - Release bars from molds. For garnish, drizzle with sweetened condensed milk and sprinkle with chopped pistachios before serving if desired.