01 - Combine mashed ube, granulated sugar, coconut milk, ube extract, and salt in a saucepan. Cook over medium heat, stirring continuously, 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, blend unsalted pistachios, whole milk, heavy cream, honey or sugar, vanilla extract, and salt until smooth. Transfer to a saucepan and gently heat over medium-low, stirring often, for about 5 minutes without boiling. Remove from heat and let cool.
03 - Pour the cooled ube mixture evenly into ice cream bar molds, filling each halfway. Freeze for 1 hour until just set. Add the pistachio mixture over the ube layer to fill molds, and insert sticks. Freeze for at least 5 hours until completely solid.
04 - Unmold bars. Optionally, drizzle with sweetened condensed milk and sprinkle with chopped pistachios prior to serving.