Over medium-high heat, boil brown sugar and 1 cup of water for 12 to 15 minutes until slightly thickened. Stir to dissolve the sugar.
Turn off the heat and add vanilla extract.
Allow the syrup to cool for a few minutes. Set it aside.
Over medium-high heat, boil 6 cups of water in a saucepan. Add sago pearls when it starts to boil; if you add them too soon, they will disintegrate. Stir them right away to prevent them from sticking together.
Cover and simmer over medium heat until translucent, about 20 minutes.
Drain and rinse under cold water to remove the residual starch.
Add about 2 tablespoons of brown sugar syrup to prevent them from clumping together. Set it aside.
Drain any excess water from the tofu. Warm in a steamer or in a microwave for about a minute, if desired.
Scoop out thin slices and portion them into cups or bowls.
Add some sago pearls and brown sugar syrup. Mix and enjoy.
Notes
Silken tofu: A coagulated soy milk made from soybeans with a delicate, smooth, and custardy texture. Choose the soft silken variety or one with just "silken tofu" on the label.
Sago: You can also use tapioca pearls, which are cooked the same way. Sago is from tropical palm trees, while tapioca is from cassava roots. Choose a small variety of sago as they tend to cook faster. After cooking, it roughly triples in volume.
Dark brown sugar: Because it contains more molasses, the caramel flavor is more pronounced. Light brown sugar can be used as a substitute.