In a small bowl, pour 1 cup unsweetened almond milk and tapioca flour. Whisk until tapioca flour is dissolved. Set aside.
In a saucepan, add 3 cups unsweetened almond milk. Bring to a simmer, then add brown sugar. Cook on medium heat until brown sugar is dissolved, stirring constantly so it doesn't stick to pan.
Add vegan butter, and cook until melted. Then add vanilla extract and salt.
Add tapioca mixture and simmer for a few minutes, or until thickened.
Let cool and pour into ramekins and place in the fridge.
Notes
After adding the tapioca flour to the pan, do not cook it for too long. It actually will break down and thin out. It only needs a few minutes to thicken.
The same goes for stirring vigorously, either during cooking or afterward. The tapioca flour will break down and the pudding will thin out. Tapioca flour is pretty touchy, but the more you work with it, the easier it becomes.
This pudding will thicken as it cools.
This pudding recipe will last 5 days in an airtight container in the fridge.