Begin by placing the small tapioca pearls in a fine-mesh strainer. Rinse them thoroughly under cold running water for about 2 minutes to prevent clumping. Set the strainer aside to allow excess water to drain off completely.

Bring a medium pot of water to a rolling boil over high heat. Once boiling, carefully add the rinsed tapioca pearls and stir gently. Cook for about 10 minutes, or until they become translucent; this indicates they are properly cooked. Remove from heat and drain the pearls.

In a medium saucepan, combine the full-fat coconut milk, whole milk, granulated sugar, and fine sea salt. Place over medium heat and gently simmer the mixture, stirring occasionally for about 5 minutes, until the sugar has dissolved and it starts to warm up.

Add the cooked tapioca pearls to the warm coconut milk mixture, stir well to ensure even distribution, then reduce the heat to low. Let simmer gently for another 10 minutes, stirring frequently.

Remove the saucepan from heat, then stir in the pure vanilla extract and any optional ingredients like coconut or pandan extract. Taste and adjust sweetness if desired.

Serve warm or chilled, ladling portions into individual bowls. Garnish with fresh fruits or toasted coconut if desired.