Place your tofu in a steamer or steam basket and steam until fully cooked through, 10-15 minutes.
While your tofu is steaming, you can work on your sago. This would depend on the kind of sago you have — some require almost an hour of cooking while others are done in 5 minutes. I provide more sago cooking tips in the post. Once your sago is done, put it aside in a bowl of cold water until you're ready to assemble.
To make the arnibal, simply combine brown sugar with water in a saucepan and bring to a gentle boil until the sugar dissolves.
Remove from heat and add 1 tsp vanilla extract, if using. Stir to combine. Set aside until you're ready to assemble.
To make taho, put tofu, sago and syrup in a mug, glass or bowl and enjoy! How much of each you put depends entirely up to you.
Video
Notes
The number of servings depend on how you layer/customize your taho.
Careful not to reduce your arnibal to a very thick syrup. It should still be easily pourable.
You can also prepare more sago or arnibal, adjust the quantities depending on how you like to take your taho.