First, plan ahead!
Place the pearl tapioca in a bowl with 1 cup (240 ml) of water and let it soak for at least 12 hours, or up to 24 hours. This step is crucial for a soft, chewy texture.
To make the ginger syrup, combine the sliced ginger, brown sugar, and 1 cup (240 ml) of water in a small saucepan.
Bring to a boil and let it simmer for about 5 minutes, allowing the flavors to infuse.
Set aside to cool completely, then strain through a fine-mesh sieve, discarding the ginger slices.
Drain any excess water from the soaked tapioca.
In a large, heavy-bottomed saucepan, combine the soaked tapioca, the prepared ginger syrup, and the coconut milk.
Cook over medium-low heat, stirring frequently.
As the mixture begins to warm and steam (but not boil), temper the eggs. Slowly pour about half a cup of the hot liquid into the beaten eggs while whisking constantly.
Then, pour the warmed egg mixture back into the saucepan, still whisking.
Continue to cook, stirring constantly, until the mixture thickens enough to coat the back of a spoon and the tapioca pearls are translucent. This can take 10-15 minutes.
Do not let it boil, or the eggs may curdle.
While the pudding cooks, sprinkle the crumbled macaroons evenly into the bottom of four individual serving glasses or a single 1. 5-quart dessert dish.
Once thickened, carefully spoon the hot tapioca pudding over the macaroon crumble.
Let it cool slightly before transferring to the refrigerator to chill completely until firm, at least 4 hours.
Don't skip the soak! Large pearl tapioca must be soaked for at least 12 hours, or it will remain hard and chalky in the center after cooking.
