Boil the boba pearls accordingly to the package instructions. If none, add 500ml water into a saucepan and heat it up until it comes to a boil. Add the uncooked pearls and stir to prevent them from sticking to one another. Within a few minutes, the pearls will float to the top.
Continue cooking the pearls for 15 minutes (or as per the package instructions). Test after 15 minutes to see if the pearls have cooked (they should be chewy and not hard in the center). If not, continue cooking for an additional 5 to 10 minutes and test again.
Once the cooking is done, turn off the heat and let the boba pearls soak in the hot water for another 15 minutes before straining them.
To make the brown sugar syrup, add the water (25ml) into a small saucepan. Add the brown sugar and cook on low heat until the sugar is all dissolved. Stir to expedite the sugar dissolving.
Continue to cook until the syrup thickens lightly (the syrup should start to bubble on the sides). Do not overcook the syrup.
Turn off the heat and add the drained boba pearls. Mix well.
To assemble the Earl Grey bubble tea, divide the boba pearls into 2 drinking glasses.
Top the boba pearls with ice cubes.
Pour in the cold milk tea and serve.