01 - In a saucepan, bring 4 cups of water to a boil. Add small black tapioca pearls and cook for 10 to 12 minutes, stirring occasionally.
02 - Drain the cooked tapioca pearls and transfer to a bowl. Stir in dark brown sugar and allow to cool completely.
03 - Heat heavy cream over medium heat until just simmering. Add black tea leaves or tea bag and steep for 5 minutes. Strain and let cool slightly.
04 - Stir sweetened condensed milk into the strained cream. Place mixture in the freezer for 20 minutes until thickened.
05 - In a microwave-safe bowl, combine glutinous rice flour, granulated sugar, and water; whisk until smooth.
06 - Cover the bowl loosely with plastic wrap. Microwave on high for 1 minute, stir, then cook for an additional 1 to 2 minutes until thick and slightly translucent.
07 - Mix in 2 tablespoons cornstarch. Set aside to cool to room temperature.
08 - Lightly dust hands and work surface with cornstarch. Divide dough into 12 equal portions and roll into balls.
09 - Flatten each dough ball into a 3-inch disk. Place 1/2 teaspoon thickened milk tea filling and a few tapioca pearls in the center. Pinch edges to seal and roll into smooth balls.
10 - Serve immediately or refrigerate in an airtight container for up to 1 day.